draft-ietf-idr-rfc5575bis-27.txt   rfc8955.txt 
IDR Working Group C. Loibl Internet Engineering Task Force (IETF) C. Loibl
Internet-Draft next layer Telekom GmbH Request for Comments: 8955 next layer Telekom GmbH
Obsoletes: 5575,7674 (if approved) S. Hares Obsoletes: 5575, 7674 S. Hares
Intended status: Standards Track Huawei Category: Standards Track Huawei
Expires: April 18, 2021 R. Raszuk ISSN: 2070-1721 R. Raszuk
Bloomberg LP NTT Network Innovations
D. McPherson D. McPherson
Verisign Verisign
M. Bacher M. Bacher
T-Mobile Austria T-Mobile Austria
October 15, 2020 December 2020
Dissemination of Flow Specification Rules Dissemination of Flow Specification Rules
draft-ietf-idr-rfc5575bis-27
Abstract Abstract
This document defines a Border Gateway Protocol Network Layer This document defines a Border Gateway Protocol Network Layer
Reachability Information (BGP NLRI) encoding format that can be used Reachability Information (BGP NLRI) encoding format that can be used
to distribute traffic Flow Specifications. This allows the routing to distribute (intra-domain and inter-domain) traffic Flow
system to propagate information regarding more specific components of Specifications for IPv4 unicast and IPv4 BGP/MPLS VPN services. This
the traffic aggregate defined by an IP destination prefix. allows the routing system to propagate information regarding more
specific components of the traffic aggregate defined by an IP
destination prefix.
It also specifies BGP Extended Community encoding formats, that can It also specifies BGP Extended Community encoding formats, which can
be used to propagate Traffic Filtering Actions along with the Flow be used to propagate Traffic Filtering Actions along with the Flow
Specification NLRI. Those Traffic Filtering Actions encode actions a Specification NLRI. Those Traffic Filtering Actions encode actions a
routing system can take if the packet matches the Flow Specification. routing system can take if the packet matches the Flow Specification.
Additionally, it defines two applications of that encoding format: This document obsoletes both RFC 5575 and RFC 7674.
one that can be used to automate inter-domain coordination of traffic
filtering, such as what is required in order to mitigate
(distributed) denial-of-service attacks, and a second application to
provide traffic filtering in the context of a BGP/MPLS VPN service.
Other applications (e.g. centralized control of traffic in a SDN or
NFV context) are also possible. Other documents may specify Flow
Specification extensions.
The information is carried via BGP, thereby reusing protocol
algorithms, operational experience, and administrative processes such
as inter-provider peering agreements.
This document obsoletes both RFC5575 and RFC7674.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on April 18, 2021. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8955.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction
2. Definitions of Terms Used in This Memo . . . . . . . . . . . 5 2. Definitions of Terms Used in This Memo
3. Flow Specifications . . . . . . . . . . . . . . . . . . . . . 5 3. Flow Specifications
4. Dissemination of IPv4 Flow Specification Information . . . . 6 4. Dissemination of IPv4 Flow Specification Information
4.1. Length Encoding . . . . . . . . . . . . . . . . . . . . . 7 4.1. Length Encoding
4.2. NLRI Value Encoding . . . . . . . . . . . . . . . . . . . 7 4.2. NLRI Value Encoding
4.2.1. Operators . . . . . . . . . . . . . . . . . . . . . . 7 4.2.1. Operators
4.2.2. Components . . . . . . . . . . . . . . . . . . . . . 9 4.2.2. Components
4.3. Examples of Encodings . . . . . . . . . . . . . . . . . . 14 4.2.2.1. Type 1 - Destination Prefix
5. Traffic Filtering . . . . . . . . . . . . . . . . . . . . . . 16 4.2.2.2. Type 2 - Source Prefix
5.1. Ordering of Flow Specifications . . . . . . . . . . . . . 17 4.2.2.3. Type 3 - IP Protocol
6. Validation Procedure . . . . . . . . . . . . . . . . . . . . 18 4.2.2.4. Type 4 - Port
7. Traffic Filtering Actions . . . . . . . . . . . . . . . . . . 19 4.2.2.5. Type 5 - Destination Port
7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 21 4.2.2.6. Type 6 - Source Port
7.2. Traffic Rate in Packets (traffic-rate-packets) sub-type 4.2.2.7. Type 7 - ICMP Type
TBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.2.8. Type 8 - ICMP Code
7.3. Traffic-action (traffic-action) sub-type 0x07 . . . . . . 21 4.2.2.9. Type 9 - TCP Flags
7.4. RT Redirect (rt-redirect) sub-type 0x08 . . . . . . . . . 22 4.2.2.10. Type 10 - Packet Length
7.5. Traffic Marking (traffic-marking) sub-type 0x09 . . . . . 23 4.2.2.11. Type 11 - DSCP (Diffserv Code Point)
7.6. Interaction with other Filtering Mechanisms in Routers . 23 4.2.2.12. Type 12 - Fragment
7.7. Considerations on Traffic Filtering Action Interference . 24 4.3. Examples of Encodings
8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks . 24 5. Traffic Filtering
9. Traffic Monitoring . . . . . . . . . . . . . . . . . . . . . 25 5.1. Ordering of Flow Specifications
10. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 25 6. Validation Procedure
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 7. Traffic Filtering Actions
11.1. AFI/SAFI Definitions . . . . . . . . . . . . . . . . . . 25 7.1. Traffic Rate in Bytes (traffic-rate-bytes) Sub-Type 0x06
11.2. Flow Component Definitions . . . . . . . . . . . . . . . 27 7.2. Traffic Rate in Packets (traffic-rate-packets) Sub-Type
11.3. Extended Community Flow Specification Actions . . . . . 28 0x0c
12. Security Considerations . . . . . . . . . . . . . . . . . . . 30 7.3. Traffic-Action (traffic-action) Sub-Type 0x07
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 32 7.4. RT Redirect (rt-redirect) Sub-Type 0x08
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32 7.5. Traffic Marking (traffic-marking) Sub-Type 0x09
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.6. Interaction with Other Filtering Mechanisms in Routers
15.1. Normative References . . . . . . . . . . . . . . . . . . 32 7.7. Considerations on Traffic Filtering Action Interference
15.2. Informative References . . . . . . . . . . . . . . . . . 34 8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks
15.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 35 9. Traffic Monitoring
Appendix A. Example Python code: flow_rule_cmp . . . . . . . . . 35 10. Error Handling
Appendix B. Comparison with RFC 5575 . . . . . . . . . . . . . . 38 11. IANA Considerations
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 11.1. AFI/SAFI Definitions
11.2. Flow Component Definitions
11.3. Extended Community Flow Specification Actions
12. Security Considerations
13. References
13.1. Normative References
13.2. Informative References
Appendix A. Example Python code: flow_rule_cmp
Appendix B. Comparison with RFC 5575
Acknowledgments
Contributors
Authors' Addresses
1. Introduction 1. Introduction
This document obsoletes "Dissemination of Flow Specification Rules" This document obsoletes "Dissemination of Flow Specification Rules"
[RFC5575] (see Appendix B for the differences). This document also [RFC5575] (see Appendix B for the differences). This document also
obsoletes "Clarification of the Flowspec Redirect Extended Community" obsoletes "Clarification of the Flowspec Redirect Extended Community"
[RFC7674] since it incorporates the encoding of the BGP Flow [RFC7674], since it incorporates the encoding of the BGP Flow
Specification Redirect Extended Community in Section 7.4. Specification Redirect Extended Community in Section 7.4.
Modern IP routers have the capability to forward traffic and to Modern IP routers have the capability to forward traffic and to
classify, shape, rate limit, filter, or redirect packets based on classify, shape, rate limit, filter, or redirect packets based on
administratively defined policies. These traffic policy mechanisms administratively defined policies. These traffic policy mechanisms
allow the operator to define match rules that operate on multiple allow the operator to define match rules that operate on multiple
fields of the packet header. Actions such as the ones described fields of the packet header. Actions, such as the ones described
above can be associated with each rule. above, can be associated with each rule.
The n-tuple consisting of the matching criteria defines an aggregate The n-tuple consisting of the matching criteria defines an aggregate
traffic Flow Specification. The matching criteria can include traffic Flow Specification. The matching criteria can include
elements such as source and destination address prefixes, IP elements such as source and destination address prefixes, IP
protocol, and transport protocol port numbers. protocol, and transport protocol port numbers.
Section 4 of this document defines a general procedure to encode Flow Section 4 of this document defines a general procedure to encode Flow
Specifications for aggregated traffic flows so that they can be Specifications for aggregated traffic flows so that they can be
distributed as a BGP [RFC4271] NLRI. Additionally, Section 7 of this distributed as a BGP [RFC4271] NLRI. Additionally, Section 7 of this
document defines the required Traffic Filtering Actions BGP Extended document defines the required Traffic Filtering Actions BGP Extended
Communities and mechanisms to use BGP for intra- and inter-provider Communities and mechanisms to use BGP for intra- and inter-provider
distribution of traffic filtering rules to filter (distributed) distribution of traffic filtering rules in order to mitigate DoS and
denial-of-service (DoS) attacks. DDoS attacks.
By expanding routing information with Flow Specifications, the By expanding routing information with Flow Specifications, the
routing system can take advantage of the ACL (Access Control List) or routing system can take advantage of the ACL (Access Control List) or
firewall capabilities in the router's forwarding path. Flow firewall capabilities in the router's forwarding path. Flow
Specifications can be seen as more specific routing entries to a Specifications can be seen as more specific routing entries to a
unicast prefix and are expected to depend upon the existing unicast unicast prefix and are expected to depend upon the existing unicast
data information. data information.
A Flow Specification received from an external autonomous system will A Flow Specification received from an external autonomous system will
need to be validated against unicast routing before being accepted need to be validated against unicast routing before being accepted
skipping to change at page 4, line 39 skipping to change at line 172
reuse both internal route distribution infrastructure (e.g., route reuse both internal route distribution infrastructure (e.g., route
reflector or confederation design) and existing external reflector or confederation design) and existing external
relationships (e.g., inter-domain BGP sessions to a customer relationships (e.g., inter-domain BGP sessions to a customer
network). network).
While it is certainly possible to address this problem using other While it is certainly possible to address this problem using other
mechanisms, this solution has been utilized in deployments because of mechanisms, this solution has been utilized in deployments because of
the substantial advantage of being an incremental addition to already the substantial advantage of being an incremental addition to already
deployed mechanisms. deployed mechanisms.
Possible applications of that extension are: Automated inter-domain
coordination of traffic filtering, such as what is required in order
to mitigate DoS and DDoS attacks or traffic filtering in the context
of a BGP/MPLS VPN service. Other applications (e.g., centralized
control of traffic in a Software-Defined Networking (SDN) or Network
Function Virtualization (NFV) context) are also possible.
In current deployments, the information distributed by this extension In current deployments, the information distributed by this extension
is originated both manually as well as automatically, the latter by is originated both manually as well as automatically, the latter by
systems that are able to detect malicious traffic flows. When systems that are able to detect malicious traffic flows. When
automated systems are used, care should be taken to ensure the automated systems are used, care should be taken to ensure the
correctness of the automated system. The the limitations of the correctness of the automated system. The limitations of the
receiving systems that need to process these automated Flow receiving systems that need to process these automated Flow
Specifications need to be taken in consideration as well (see also Specifications need to be taken in consideration as well (see also
Section 12). Section 12).
This specification defines required protocol extensions to address This specification defines required protocol extensions to address
most common applications of IPv4 unicast and VPNv4 unicast filtering. most common applications of IPv4 unicast and VPNv4 unicast filtering.
The same mechanism can be reused and new match criteria added to The same mechanism can be reused and new match criteria added to
address similar filtering needs for other BGP address families such address similar filtering needs for other BGP address families, such
as IPv6 families [I-D.ietf-idr-flow-spec-v6]. as IPv6 families [RFC8956].
2. Definitions of Terms Used in This Memo 2. Definitions of Terms Used in This Memo
AFI - Address Family Identifier. AFI: Address Family Identifier
AS - Autonomous System. AS: Autonomous System
Loc-RIB - The Loc-RIB contains the routes that have been selected Loc-RIB: The Loc-RIB contains the routes that have been selected by
by the local BGP speaker's Decision Process [RFC4271]. the local BGP speaker's Decision Process [RFC4271].
NLRI - Network Layer Reachability Information. NLRI: Network Layer Reachability Information
PE - Provider Edge router. PE: Provider Edge router
RIB - Routing Information Base. RIB: Routing Information Base
SAFI - Subsequent Address Family Identifier. SAFI: Subsequent Address Family Identifier
VRF - Virtual Routing and Forwarding instance. VRF: Virtual Routing and Forwarding
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Flow Specifications 3. Flow Specifications
A Flow Specification is an n-tuple consisting of several matching A Flow Specification is an n-tuple consisting of several matching
criteria that can be applied to IP traffic. A given IP packet is criteria that can be applied to IP traffic. A given IP packet is
said to match the defined Flow Specification if it matches all the said to match the defined Flow Specification if it matches all the
specified criteria. This n-tuple is encoded into a BGP NLRI defined specified criteria. This n-tuple is encoded into a BGP NLRI defined
below. below.
A given Flow Specification may be associated with a set of A given Flow Specification may be associated with a set of
attributes, depending on the particular application; such attributes attributes, depending on the particular application; such attributes
may or may not include reachability information (i.e., NEXT_HOP). may or may not include reachability information (i.e., NEXT_HOP).
Well-known or AS-specific community attributes can be used to encode Well-known or AS-specific community attributes can be used to encode
a set of predetermined actions. a set of predetermined actions.
A particular application is identified by a specific (Address Family A particular application is identified by a specific (Address Family
Identifier, Subsequent Address Family Identifier (AFI, SAFI)) pair Identifier, Subsequent Address Family Identifier (AFI, SAFI)) pair
[RFC4760] and corresponds to a distinct set of RIBs. Those RIBs [RFC4760] and corresponds to a distinct set of RIBs. Those RIBs
should be treated independently from each other in order to assure should be treated independently from each other in order to assure
non-interference between distinct applications. noninterference between distinct applications.
BGP itself treats the NLRI as a key to an entry in its databases. BGP itself treats the NLRI as a key to an entry in its databases.
Entries that are placed in the Loc-RIB are then associated with a Entries that are placed in the Loc-RIB are then associated with a
given set of semantics, which is application dependent. This is given set of semantics, which is application dependent. This is
consistent with existing BGP applications. For instance, IP unicast consistent with existing BGP applications. For instance, IP unicast
routing (AFI=1, SAFI=1) and IP multicast reverse-path information routing (AFI=1, SAFI=1) and IP multicast reverse-path information
(AFI=1, SAFI=2) are handled by BGP without any particular semantics (AFI=1, SAFI=2) are handled by BGP without any particular semantics
being associated with them until installed in the Loc-RIB. being associated with them until installed in the Loc-RIB.
Standard BGP policy mechanisms, such as UPDATE filtering by NLRI Standard BGP policy mechanisms, such as UPDATE filtering by NLRI
prefix as well as community matching and must apply to the Flow prefix as well as community matching, must apply to the Flow
specification defined NLRI-type. Network operators can also control specification defined NLRI-type. Network operators can also control
propagation of such routing updates by enabling or disabling the propagation of such routing updates by enabling or disabling the
exchange of a particular (AFI, SAFI) pair on a given BGP peering exchange of a particular (AFI, SAFI) pair on a given BGP peering
session. session.
4. Dissemination of IPv4 Flow Specification Information 4. Dissemination of IPv4 Flow Specification Information
This document defines a Flow Specification NLRI type (Figure 1) that This document defines a Flow Specification NLRI type (Figure 1) that
may include several components such as destination prefix, source may include several components, such as destination prefix, source
prefix, protocol, ports, and others (see Section 4.2 below). prefix, protocol, ports, and others (see Section 4.2 below).
This NLRI information is encoded using MP_REACH_NLRI and This NLRI information is encoded using MP_REACH_NLRI and
MP_UNREACH_NLRI attributes as defined in [RFC4760]. When advertising MP_UNREACH_NLRI attributes, as defined in [RFC4760]. When
Flow Specifications, the Length of Next Hop Network Address MUST be advertising Flow Specifications, the Length of the Next-Hop Network
set to 0. The Network Address of Next Hop field MUST be ignored. Address MUST be set to 0. The Network Address of the Next-Hop field
MUST be ignored.
The NLRI field of the MP_REACH_NLRI and MP_UNREACH_NLRI is encoded as The NLRI field of the MP_REACH_NLRI and MP_UNREACH_NLRI is encoded as
one or more 2-tuples of the form <length, NLRI value>. It consists one or more 2-tuples of the form <length, NLRI value>. It consists
of a 1- or 2-octet length field followed by a variable-length NLRI of a 1- or 2-octet length field followed by a variable-length NLRI
value. The length is expressed in octets. value. The length is expressed in octets.
+-------------------------------+ +-------------------------------+
| length (0xnn or 0xfnnn) | | length (0xnn or 0xfnnn) |
+-------------------------------+ +-------------------------------+
| NLRI value (variable) | | NLRI value (variable) |
+-------------------------------+ +-------------------------------+
Figure 1: Flow Specification NLRI for IPv4 Figure 1: Flow Specification NLRI for IPv4
Implementations wishing to exchange Flow Specification MUST use BGP's Implementations wishing to exchange Flow Specification MUST use BGP's
Capability Advertisement facility to exchange the Multiprotocol Capability Advertisement facility to exchange the Multiprotocol
Extension Capability Code (Code 1) as defined in [RFC4760]. The Extension Capability Code (Code 1), as defined in [RFC4760]. The
(AFI, SAFI) pair carried in the Multiprotocol Extension Capability (AFI, SAFI) pair carried in the Multiprotocol Extension Capability
MUST be (AFI=1, SAFI=133) for IPv4 Flow Specification, and (AFI=1, MUST be (AFI=1, SAFI=133) for IPv4 Flow Specification and (AFI=1,
SAFI=134) for VPNv4 Flow Specification. SAFI=134) for VPNv4 Flow Specification.
4.1. Length Encoding 4.1. Length Encoding
o If the NLRI length is smaller than 240 (0xf0 hex) octets, the The length field indicates the length in octets of the variable NLRI
value:
* If the NLRI length is smaller than 240 (0xf0 hex) octets, the
length field can be encoded as a single octet. length field can be encoded as a single octet.
o Otherwise, it is encoded as an extended-length 2-octet value in * Otherwise, it is encoded as an extended-length 2-octet value in
which the most significant nibble has the hex value 0xf. which the most significant nibble has the hex value 0xf.
In Figure 1 above, values less-than 240 are encoded using two hex In Figure 1 above, values less than 240 are encoded using two hex
digits (0xnn). Values above 239 are encoded using 3 hex digits digits (0xnn). Values above 239 are encoded using 3 hex digits
(0xfnnn). The highest value that can be represented with this (0xfnnn). The highest value that can be represented with this
encoding is 4095. For example the length value of 239 is encoded as encoding is 4095. For example, the length value of 239 is encoded as
0xef (single octet) while 240 is encoded as 0xf0f0 (2-octet). 0xef (single octet), while 240 is encoded as 0xf0f0 (2 octets).
4.2. NLRI Value Encoding 4.2. NLRI Value Encoding
The Flow Specification NLRI value consists of a list of optional The Flow Specification NLRI value consists of a list of optional
components and is encoded as follows: components and is encoded as follows:
Encoding: <[component]+> Encoding: <[component]+>
A specific packet is considered to match the Flow Specification when A specific packet is considered to match the Flow Specification when
it matches the intersection (AND) of all the components present in it matches the intersection (AND) of all the components present in
the Flow Specification. the Flow Specification.
Components MUST follow strict type ordering by increasing numerical Components MUST follow strict type ordering by increasing numerical
order. A given component type MAY (exactly once) be present in the order. A given component type MAY (exactly once) be present in the
Flow Specification. If present, it MUST precede any component of Flow Specification. If present, it MUST precede any component of
higher numeric type value. higher numeric type value.
All combinations of components within a single Flow Specification are All combinations of components within a single Flow Specification are
allowed. However, some combinations cannot match any packets (e.g. allowed. However, some combinations cannot match any packets (e.g.,
"ICMP Type AND Port" will never match any packets), and thus SHOULD "ICMP Type AND Port" will never match any packets) and thus SHOULD
NOT be propagated by BGP. NOT be propagated by BGP.
A NLRI value not encoded as specified here, including a NLRI that An NLRI value not encoded as specified here, including an NLRI that
contains an unknown component type, is considered malformed and error contains an unknown component type, is considered malformed and error
handling according to Section 10 is performed. handling according to Section 10 is performed.
4.2.1. Operators 4.2.1. Operators
Most of the components described below make use of comparison Most of the components described below make use of comparison
operators. Which of the two operators is used is defined by the operators. Which of the two operators is used is defined by the
components in Section 4.2.2. The operators are encoded as a single components in Section 4.2.2. The operators are encoded as a single
octet. octet.
skipping to change at page 8, line 16 skipping to change at line 346
This operator is encoded as shown in Figure 2. This operator is encoded as shown in Figure 2.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| e | a | len | 0 |lt |gt |eq | | e | a | len | 0 |lt |gt |eq |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 2: Numeric Operator (numeric_op) Figure 2: Numeric Operator (numeric_op)
e - end-of-list bit: Set in the last {op, value} pair in the list. e (end-of-list bit): Set in the last {op, value} pair in the list
a - AND bit: If unset, the result of the previous {op, value} pair a (AND bit): If unset, the result of the previous {op, value} pair
is logically ORed with the current one. If set, the operation is is logically ORed with the current one. If set, the operation
a logical AND. In the first operator octet of a sequence it MUST is a logical AND. In the first operator octet of a sequence,
be encoded as unset and MUST be treated as always unset on it MUST be encoded as unset and MUST be treated as always unset
decoding. The AND operator has higher priority than OR for the on decoding. The AND operator has higher priority than OR for
purposes of evaluating logical expressions. the purposes of evaluating logical expressions.
len - length: The length of the value field for this operator given len (length): The length of the value field for this operator given
as (1 << len). This encodes 1 (len=00), 2 (len=01), 4 (len=10), 8 as (1 << len). This encodes 1 (len=00), 2 (len=01), 4
(len=11) octets. (len=10), and 8 (len=11) octets.
0 - MUST be set to 0 on NLRI encoding, and MUST be ignored during 0: MUST be set to 0 on NLRI encoding and MUST be ignored during
decoding decoding
lt - less than comparison between data and value. lt: less-than comparison between data and value
gt - greater than comparison between data and value. gt: greater-than comparison between data and value
eq - equality between data and value. eq: equality between data and value
The bits lt, gt, and eq can be combined to produce common relational The bits lt, gt, and eq can be combined to produce common relational
operators such as "less or equal", "greater or equal", and "not equal operators, such as "less or equal", "greater or equal", and "not
to" as shown in Table 1. equal to", as shown in Table 1.
+----+----+----+-----------------------------------+ +====+====+====+==================================+
| lt | gt | eq | Resulting operation | | lt | gt | eq | Resulting operation |
+----+----+----+-----------------------------------+ +====+====+====+==================================+
| 0 | 0 | 0 | false (independent of the value) | | 0 | 0 | 0 | false (independent of the value) |
| 0 | 0 | 1 | == (equal) | +----+----+----+----------------------------------+
| 0 | 1 | 0 | > (greater than) | | 0 | 0 | 1 | == (equal) |
| 0 | 1 | 1 | >= (greater than or equal) | +----+----+----+----------------------------------+
| 1 | 0 | 0 | < (less than) | | 0 | 1 | 0 | > (greater than) |
| 1 | 0 | 1 | <= (less than or equal) | +----+----+----+----------------------------------+
| 1 | 1 | 0 | != (not equal value) | | 0 | 1 | 1 | >= (greater than or equal) |
| 1 | 1 | 1 | true (independent of the value) | +----+----+----+----------------------------------+
+----+----+----+-----------------------------------+ | 1 | 0 | 0 | < (less than) |
+----+----+----+----------------------------------+
| 1 | 0 | 1 | <= (less than or equal) |
+----+----+----+----------------------------------+
| 1 | 1 | 0 | != (not equal value) |
+----+----+----+----------------------------------+
| 1 | 1 | 1 | true (independent of the value) |
+----+----+----+----------------------------------+
Table 1: Comparison operation combinations Table 1: Comparison Operation Combinations
4.2.1.2. Bitmask Operator (bitmask_op) 4.2.1.2. Bitmask Operator (bitmask_op)
This operator is encoded as shown in Figure 3. This operator is encoded as shown in Figure 3.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| e | a | len | 0 | 0 |not| m | | e | a | len | 0 | 0 |not| m |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 3: Bitmask Operator (bitmask_op) Figure 3: Bitmask Operator (bitmask_op)
e, a, len - Most significant nibble: (end-of-list bit, AND bit, and e, a, len (end-of-list bit, AND bit, and length field): Most
length field), as defined in the Numeric Operator format in significant nibble; defined in the Numeric Operator format in
Section 4.2.1.1. Section 4.2.1.1.
not - NOT bit: If set, logical negation of operation. not (NOT bit): If set, logical negation of operation.
m - Match bit: If set, this is a bitwise match operation defined as m (Match bit): If set, this is a bitwise match operation defined as
"(data AND value) == value"; if unset, (data AND value) evaluates "(data AND value) == value"; if unset, (data AND value)
to TRUE if any of the bits in the value mask are set in the data evaluates to TRUE if any of the bits in the value mask are set
in the data.
0 - all 0 bits: MUST be set to 0 on NLRI encoding, and MUST be 0 (all 0 bits): MUST be set to 0 on NLRI encoding and MUST be
ignored during decoding ignored during decoding
4.2.2. Components 4.2.2. Components
The encoding of each of the components begins with a type field (1 The encoding of each of the components begins with a type field (1
octet) followed by a variable length parameter. The following octet) followed by a variable length parameter. The following
sections define component types and parameter encodings for the IPv4 sections define component types and parameter encodings for the IPv4
IP layer and transport layer headers. IPv6 NLRI component types are IP layer and transport layer headers. IPv6 NLRI component types are
described in [I-D.ietf-idr-flow-spec-v6]. described in [RFC8956].
4.2.2.1. Type 1 - Destination Prefix 4.2.2.1. Type 1 - Destination Prefix
Encoding: <type (1 octet), length (1 octet), prefix (variable)> Encoding: <type (1 octet), length (1 octet), prefix (variable)>
Defines the destination prefix to match. The length and prefix Defines the destination prefix to match. The length and prefix
fields are encoded as in BGP UPDATE messages [RFC4271] fields are encoded as in BGP UPDATE messages [RFC4271].
4.2.2.2. Type 2 - Source Prefix 4.2.2.2. Type 2 - Source Prefix
Encoding: <type (1 octet), length (1 octet), prefix (variable)> Encoding: <type (1 octet), length (1 octet), prefix (variable)>
Defines the source prefix to match. The length and prefix fields are Defines the source prefix to match. The length and prefix fields are
encoded as in BGP UPDATE messages [RFC4271] encoded as in BGP UPDATE messages [RFC4271].
4.2.2.3. Type 3 - IP Protocol 4.2.2.3. Type 3 - IP Protocol
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Contains a list of {numeric_op, value} pairs that are used to match Contains a list of {numeric_op, value} pairs that are used to match
the IP protocol value octet in IP packet header (see [RFC0791] the IP protocol value octet in IP packet header (see Section 3.1 of
Section 3.1). [RFC0791]).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 3 component values SHOULD be encoded as single Section 4.2.1.1. Type 3 component values SHOULD be encoded as single
octet (numeric_op len=00). octet (numeric_op len=00).
4.2.2.4. Type 4 - Port 4.2.2.4. Type 4 - Port
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs that matches source OR Defines a list of {numeric_op, value} pairs that match source OR
destination TCP/UDP ports (see [RFC0793] Section 3.1 and [RFC0768] destination TCP/UDP ports (see Section 3.1 of [RFC0793] and the
Section "Format"). This component matches if either the destination "Format" section of [RFC0768]). This component matches if either the
port OR the source port of a IP packet matches the value. destination port OR the source port of an IP packet matches the
value.
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 4 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 4 component values SHOULD be encoded as 1- or
2-octet quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
In case of the presence of the port (destination-port In case of the presence of the port (destination-port
Section 4.2.2.5, source-port Section 4.2.2.6) component only TCP or (Section 4.2.2.5), source-port (Section 4.2.2.6)) component, only TCP
UDP packets can match the entire Flow Specification. The port or UDP packets can match the entire Flow Specification. The port
component, if present, never matches when the packet's IP protocol component, if present, never matches when the packet's IP protocol
value is not 6 (TCP) or 17 (UDP), if the packet is fragmented and value is not 6 (TCP) or 17 (UDP), if the packet is fragmented and
this is not the first fragment, or if the system is unable to locate this is not the first fragment, or if the system is unable to locate
the transport header. Different implementations may or may not be the transport header. Different implementations may or may not be
able to decode the transport header in the presence of IP options or able to decode the transport header in the presence of IP options or
Encapsulating Security Payload (ESP) NULL [RFC4303] encryption. Encapsulating Security Payload (ESP) NULL [RFC4303] encryption.
4.2.2.5. Type 5 - Destination Port 4.2.2.5. Type 5 - Destination Port
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the Defines a list of {numeric_op, value} pairs used to match the
destination port of a TCP or UDP packet (see also [RFC0793] destination port of a TCP or UDP packet (see also Section 3.1 of
Section 3.1 and [RFC0768] Section "Format"). [RFC0793] and the "Format" section of [RFC0768].
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 5 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 5 component values SHOULD be encoded as 1- or
2-octet quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
The last paragraph of Section 4.2.2.4 also applies to this component. The last paragraph of Section 4.2.2.4 also applies to this component.
4.2.2.6. Type 6 - Source Port 4.2.2.6. Type 6 - Source Port
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the source Defines a list of {numeric_op, value} pairs used to match the source
port of a TCP or UDP packet (see also [RFC0793] Section 3.1 and port of a TCP or UDP packet (see also Section 3.1 of [RFC0793] and
[RFC0768] Section "Format"). the "Format" section of [RFC0768].
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 6 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 6 component values SHOULD be encoded as 1- or
2-octet quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
The last paragraph of Section 4.2.2.4 also applies to this component. The last paragraph of Section 4.2.2.4 also applies to this component.
4.2.2.7. Type 7 - ICMP type 4.2.2.7. Type 7 - ICMP Type
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the type Defines a list of {numeric_op, value} pairs used to match the type
field of an ICMP packet (see also [RFC0792] Section "Message field of an ICMP packet (see also the "Message Formats" section of
Formats"). [RFC0792]).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 7 component values SHOULD be encoded as single Section 4.2.1.1. Type 7 component values SHOULD be encoded as single
octet (numeric_op len=00). octet (numeric_op len=00).
In case of the presence of the ICMP type component only ICMP packets In case of the presence of the ICMP type component, only ICMP packets
can match the entire Flow Specification. The ICMP type component, if can match the entire Flow Specification. The ICMP type component, if
present, never matches when the packet's IP protocol value is not 1 present, never matches when the packet's IP protocol value is not 1
(ICMP), if the packet is fragmented and this is not the first (ICMP), if the packet is fragmented and this is not the first
fragment, or if the system is unable to locate the transport header. fragment, or if the system is unable to locate the transport header.
Different implementations may or may not be able to decode the Different implementations may or may not be able to decode the
transport header in the presence of IP options or Encapsulating transport header in the presence of IP options or Encapsulating
Security Payload (ESP) NULL [RFC4303] encryption. Security Payload (ESP) NULL [RFC4303] encryption.
4.2.2.8. Type 8 - ICMP code 4.2.2.8. Type 8 - ICMP Code
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the code Defines a list of {numeric_op, value} pairs used to match the code
field of an ICMP packet (see also [RFC0792] Section "Message field of an ICMP packet (see also the "Message Formats" section of
Formats"). [RFC0792]).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 8 component values SHOULD be encoded as single Section 4.2.1.1. Type 8 component values SHOULD be encoded as single
octet (numeric_op len=00). octet (numeric_op len=00).
In case of the presence of the ICMP code component only ICMP packets In case of the presence of the ICMP code component, only ICMP packets
can match the entire Flow Specification. The ICMP code component, if can match the entire Flow Specification. The ICMP code component, if
present, never matches when the packet's IP protocol value is not 1 present, never matches when the packet's IP protocol value is not 1
(ICMP), if the packet is fragmented and this is not the first (ICMP), if the packet is fragmented and this is not the first
fragment, or if the system is unable to locate the transport header. fragment, or if the system is unable to locate the transport header.
Different implementations may or may not be able to decode the Different implementations may or may not be able to decode the
transport header in the presence of IP options or Encapsulating transport header in the presence of IP options or Encapsulating
Security Payload (ESP) NULL [RFC4303] encryption. Security Payload (ESP) NULL [RFC4303] encryption.
4.2.2.9. Type 9 - TCP flags 4.2.2.9. Type 9 - TCP Flags
Encoding: <type (1 octet), [bitmask_op, bitmask]+> Encoding: <type (1 octet), [bitmask_op, bitmask]+>
Defines a list of {bitmask_op, bitmask} pairs used to match TCP Defines a list of {bitmask_op, bitmask} pairs used to match TCP
Control Bits (see also [RFC0793] Section 3.1). control bits (see also Section 3.1 of [RFC0793]).
This component uses the Bitmask Operator (bitmask_op) described in This component uses the Bitmask Operator (bitmask_op) described in
Section 4.2.1.2. Type 9 component bitmasks MUST be encoded as 1- or Section 4.2.1.2. Type 9 component bitmasks MUST be encoded as 1- or
2-octet bitmask (bitmask_op len=00 or len=01). 2-octet bitmask (bitmask_op len=00 or len=01).
When a single octet (bitmask_op len=00) is specified, it matches When a single octet (bitmask_op len=00) is specified, it matches
octet 14 of the TCP header (see also [RFC0793] Section 3.1), which octet 14 of the TCP header (see also Section 3.1 of [RFC0793]), which
contains the TCP Control Bits. When a 2-octet (bitmask_op len=01) contains the TCP control bits. When a 2-octet (bitmask_op len=01)
encoding is used, it matches octets 13 and 14 of the TCP header with encoding is used, it matches octets 13 and 14 of the TCP header with
the data offset (leftmost 4 bits) always treated as 0. the data offset (leftmost 4 bits) always treated as 0.
In case of the presence of the TCP flags component only TCP packets In case of the presence of the TCP flags component, only TCP packets
can match the entire Flow Specification. The TCP flags component, if can match the entire Flow Specification. The TCP flags component, if
present, never matches when the packet's IP protocol value is not 6 present, never matches when the packet's IP protocol value is not 6
(TCP), if the packet is fragmented and this is not the first (TCP), if the packet is fragmented and this is not the first
fragment, or if the system is unable to locate the transport header. fragment, or if the system is unable to locate the transport header.
Different implementations may or may not be able to decode the Different implementations may or may not be able to decode the
transport header in the presence of IP options or Encapsulating transport header in the presence of IP options or Encapsulating
Security Payload (ESP) NULL [RFC4303] encryption. Security Payload (ESP) NULL [RFC4303] encryption.
4.2.2.10. Type 10 - Packet length 4.2.2.10. Type 10 - Packet Length
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match on the Defines a list of {numeric_op, value} pairs used to match on the
total IP packet length (excluding Layer 2 but including IP header). total IP packet length (excluding Layer 2 but including IP header).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 10 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 10 component values SHOULD be encoded as 1- or
2-octet quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
skipping to change at page 13, line 46 skipping to change at line 614
This component uses the Bitmask Operator (bitmask_op) described in This component uses the Bitmask Operator (bitmask_op) described in
Section 4.2.1.2. The Type 12 component bitmask MUST be encoded as Section 4.2.1.2. The Type 12 component bitmask MUST be encoded as
single octet bitmask (bitmask_op len=00). single octet bitmask (bitmask_op len=00).
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | 0 | 0 | 0 |LF |FF |IsF|DF | | 0 | 0 | 0 | 0 |LF |FF |IsF|DF |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 4: Fragment Bitmask Operand Figure 4: Fragment Bitmask Operand
Bitmask values: Bitmask values:
DF - Don't fragment - match if [RFC0791] IP Header Flags Bit-1 (DF) DF (Don't Fragment): match if IP Header Flags Bit-1 (DF) [RFC0791]
is 1 is 1
IsF - Is a fragment other than the first - match if [RFC0791] IP IsF (Is a fragment other than the first): match if the [RFC0791] IP
Header Fragment Offset is not 0 Header Fragment Offset is not 0
FF - First fragment - match if [RFC0791] IP Header Fragment Offset FF (First Fragment): match if the [RFC0791] IP Header Fragment
is 0 AND Flags Bit-2 (MF) is 1 Offset is 0 AND Flags Bit-2 (MF) is 1
LF - Last fragment - match if [RFC0791] IP Header Fragment Offset is LF (Last Fragment): match if the [RFC0791] IP Header Fragment Offset
not 0 AND Flags Bit-2 (MF) is 0 is not 0 AND Flags Bit-2 (MF) is 0
0 - MUST be set to 0 on NLRI encoding, and MUST be ignored during 0: MUST be set to 0 on NLRI encoding and MUST be ignored during
decoding decoding
4.3. Examples of Encodings 4.3. Examples of Encodings
4.3.1. Example 1 4.3.1. Example 1
An example of a Flow Specification NLRI encoding for: "all packets to An example of a Flow Specification NLRI encoding for: "all packets to
192.0.2.0/24 and TCP port 25". 192.0.2.0/24 and TCP port 25".
+--------+----------------+----------+----------+ +========+================+==========+==========+
| length | destination | protocol | port | | length | destination | protocol | port |
+--------+----------------+----------+----------+ +========+================+==========+==========+
| 0x0b | 01 18 c0 00 02 | 03 81 06 | 04 81 19 | | 0x0b | 01 18 c0 00 02 | 03 81 06 | 04 81 19 |
+--------+----------------+----------+----------+ +--------+----------------+----------+----------+
Table 2
Decoded: Decoded:
+-------+------------+-------------------------------+ +=======+==============================================+
| Value | | | | Value | |
+-------+------------+-------------------------------+ +=======+============+=================================+
| 0x0b | length | 11 octets (len<240 1-octet) | | 0x0b | length | 11 octets (if len<240, 1 octet) |
| 0x01 | type | Type 1 - Destination Prefix | +-------+------------+---------------------------------+
| 0x18 | length | 24 bit | | 0x01 | type | Type 1 - Destination Prefix |
| 0xc0 | prefix | 192 | +-------+------------+---------------------------------+
| 0x00 | prefix | 0 | | 0x18 | length | 24 bit |
| 0x02 | prefix | 2 | +-------+------------+---------------------------------+
| 0x03 | type | Type 3 - IP Protocol | | 0xc0 | prefix | 192 |
| 0x81 | numeric_op | end-of-list, value size=1, == | +-------+------------+---------------------------------+
| 0x06 | value | 6 (TCP) | | 0x00 | prefix | 0 |
| 0x04 | type | Type 4 - Port | +-------+------------+---------------------------------+
| 0x81 | numeric_op | end-of-list, value size=1, == | | 0x02 | prefix | 2 |
| 0x19 | value | 25 | +-------+------------+---------------------------------+
+-------+------------+-------------------------------+ | 0x03 | type | Type 3 - IP Protocol |
+-------+------------+---------------------------------+
| 0x81 | numeric_op | end-of-list, value size=1, == |
+-------+------------+---------------------------------+
| 0x06 | value | 6 (TCP) |
+-------+------------+---------------------------------+
| 0x04 | type | Type 4 - Port |
+-------+------------+---------------------------------+
| 0x81 | numeric_op | end-of-list, value size=1, == |
+-------+------------+---------------------------------+
| 0x19 | value | 25 |
+-------+------------+---------------------------------+
This constitutes a NLRI with a NLRI length of 11 octets. Table 3
This constitutes an NLRI with an NLRI length of 11 octets.
4.3.2. Example 2 4.3.2. Example 2
An example of a Flow Specification NLRI encoding for: "all packets to An example of a Flow Specification NLRI encoding for: "all packets to
192.0.2.0/24 from 203.0.113.0/24 and port {range [137, 139] or 192.0.2.0/24 from 203.0.113.0/24 and port {range [137, 139] or
8080}". 8080}".
+--------+----------------+----------------+-------------------------+ +========+================+================+=============+
| length | destination | source | port | | length | destination | source | port |
+--------+----------------+----------------+-------------------------+ +========+================+================+=============+
| 0x12 | 01 18 c0 00 02 | 02 18 cb 00 71 | 04 03 89 45 8b 91 1f 90 | | 0x12 | 01 18 c0 00 02 | 02 18 cb 00 71 | 04 03 89 45 |
+--------+----------------+----------------+-------------------------+ | | | | 8b 91 1f 90 |
+--------+----------------+----------------+-------------+
Table 4
Decoded: Decoded:
+--------+------------+-------------------------------+ +========+==============================================+
| Value | | | | Value | |
+--------+------------+-------------------------------+ +========+============+=================================+
| 0x12 | length | 18 octets (len<240 1-octet) | | 0x12 | length | 18 octets (if len<240, 1 octet) |
| 0x01 | type | Type 1 - Destination Prefix | +--------+------------+---------------------------------+
| 0x18 | length | 24 bit | | 0x01 | type | Type 1 - Destination Prefix |
| 0xc0 | prefix | 192 | +--------+------------+---------------------------------+
| 0x00 | prefix | 0 | | 0x18 | length | 24 bit |
| 0x02 | prefix | 2 | +--------+------------+---------------------------------+
| 0x02 | type | Type 2 - Source Prefix | | 0xc0 | prefix | 192 |
| 0x18 | length | 24 bit | +--------+------------+---------------------------------+
| 0xcb | prefix | 203 | | 0x00 | prefix | 0 |
| 0x00 | prefix | 0 | +--------+------------+---------------------------------+
| 0x71 | prefix | 113 | | 0x02 | prefix | 2 |
| 0x04 | type | Type 4 - Port | +--------+------------+---------------------------------+
| 0x03 | numeric_op | value size=1, >= | | 0x02 | type | Type 2 - Source Prefix |
| 0x89 | value | 137 | +--------+------------+---------------------------------+
| 0x45 | numeric_op | "AND", value size=1, <= | | 0x18 | length | 24 bit |
| 0x8b | value | 139 | +--------+------------+---------------------------------+
| 0x91 | numeric_op | end-of-list, value size=2, == | | 0xcb | prefix | 203 |
| 0x1f90 | value | 8080 | +--------+------------+---------------------------------+
+--------+------------+-------------------------------+ | 0x00 | prefix | 0 |
+--------+------------+---------------------------------+
| 0x71 | prefix | 113 |
+--------+------------+---------------------------------+
| 0x04 | type | Type 4 - Port |
+--------+------------+---------------------------------+
| 0x03 | numeric_op | value size=1, >= |
+--------+------------+---------------------------------+
| 0x89 | value | 137 |
+--------+------------+---------------------------------+
| 0x45 | numeric_op | "AND", value size=1, <= |
+--------+------------+---------------------------------+
| 0x8b | value | 139 |
+--------+------------+---------------------------------+
| 0x91 | numeric_op | end-of-list, value size=2, == |
+--------+------------+---------------------------------+
| 0x1f90 | value | 8080 |
+--------+------------+---------------------------------+
This constitutes a NLRI with a NLRI length of 18 octets. Table 5
This constitutes an NLRI with an NLRI length of 18 octets.
4.3.3. Example 3 4.3.3. Example 3
An example of a Flow Specification NLRI encoding for: "all packets to An example of a Flow Specification NLRI encoding for: "all packets to
192.0.2.1/32 and fragment { DF or FF } (matching packet with DF bit 192.0.2.1/32 and fragment { DF or FF } (matching packet with DF bit
set or First Fragments) set or First Fragments)
+--------+-------------------+----------+
| length | destination | fragment | +========+===================+==========+
+--------+-------------------+----------+ | length | destination | fragment |
| 0x09 | 01 20 c0 00 02 01 | 0c 80 05 | +========+===================+==========+
+--------+-------------------+----------+ | 0x09 | 01 20 c0 00 02 01 | 0c 80 05 |
+--------+-------------------+----------+
Table 6
Decoded: Decoded:
+-------+------------+------------------------------+ +=======+=============================================+
| Value | | | | Value | |
+-------+------------+------------------------------+ +=======+============+================================+
| 0x09 | length | 9 octets (len<240 1-octet) | | 0x09 | length | 9 octets (if len<240, 1 octet) |
| 0x01 | type | Type 1 - Destination Prefix | +-------+------------+--------------------------------+
| 0x20 | length | 32 bit | | 0x01 | type | Type 1 - Destination Prefix |
| 0xc0 | prefix | 192 | +-------+------------+--------------------------------+
| 0x00 | prefix | 0 | | 0x20 | length | 32 bit |
| 0x02 | prefix | 2 | +-------+------------+--------------------------------+
| 0x01 | prefix | 1 | | 0xc0 | prefix | 192 |
| 0x0c | type | Type 12 - Fragment | +-------+------------+--------------------------------+
| 0x80 | bitmask_op | end-of-list, value size=1 | | 0x00 | prefix | 0 |
| 0x05 | bitmask | DF=1, FF=1 | +-------+------------+--------------------------------+
+-------+------------+------------------------------+ | 0x02 | prefix | 2 |
+-------+------------+--------------------------------+
| 0x01 | prefix | 1 |
+-------+------------+--------------------------------+
| 0x0c | type | Type 12 - Fragment |
+-------+------------+--------------------------------+
| 0x80 | bitmask_op | end-of-list, value size=1 |
+-------+------------+--------------------------------+
| 0x05 | bitmask | DF=1, FF=1 |
+-------+------------+--------------------------------+
This constitutes a NLRI with a NLRI length of 9 octets. Table 7
This constitutes an NLRI with an NLRI length of 9 octets.
5. Traffic Filtering 5. Traffic Filtering
Traffic filtering policies have been traditionally considered to be Traffic filtering policies have been traditionally considered to be
relatively static. Limitations of these static mechanisms caused relatively static. Limitations of these static mechanisms caused
this new dynamic mechanism to be designed for the three new this new dynamic mechanism to be designed for the three new
applications of traffic filtering: applications of traffic filtering:
o Prevention of traffic-based, denial-of-service (DOS) attacks. * Prevention of traffic-based, denial-of-service (DoS) attacks
o Traffic filtering in the context of BGP/MPLS VPN service. * Traffic filtering in the context of BGP/MPLS VPN service
o Centralized traffic control for SDN/NFV networks. * Centralized traffic control for SDN/NFV networks
These applications require coordination among service providers and/ These applications require coordination among service providers and/
or coordination among the AS within a service provider. or coordination among the AS within a service provider.
The Flow Specification NLRI defined in Section 4 conveys information The Flow Specification NLRI defined in Section 4 conveys information
about traffic filtering rules for traffic that should be discarded or about traffic filtering rules for traffic that should be discarded or
handled in a manner specified by a set of pre-defined actions (which handled in a manner specified by a set of predefined actions (which
are defined in BGP Extended Communities). This mechanism is are defined in BGP Extended Communities). This mechanism is
primarily designed to allow an upstream autonomous system to perform primarily designed to allow an upstream autonomous system to perform
inbound filtering in their ingress routers of traffic that a given inbound filtering in their ingress routers of traffic that a given
downstream AS wishes to drop. downstream AS wishes to drop.
In order to achieve this goal, this document specifies two In order to achieve this goal, this document specifies two
application-specific NLRI identifiers that provide traffic filters, application-specific NLRI identifiers that provide traffic filters
and a set of actions encoding in BGP Extended Communities. The two and a set of actions encoding in BGP Extended Communities. The two
application-specific NLRI identifiers are: application-specific NLRI identifiers are:
o IPv4 Flow Specification identifier (AFI=1, SAFI=133) along with * IPv4 Flow Specification identifier (AFI=1, SAFI=133) along with
specific semantic rules for IPv4 routes, and specific semantic rules for IPv4 routes and
o VPNv4 Flow Specification identifier (AFI=1, SAFI=134) value, which * VPNv4 Flow Specification identifier (AFI=1, SAFI=134) value, which
can be used to propagate traffic filtering information in a BGP/ can be used to propagate traffic filtering information in a BGP/
MPLS VPN environment. MPLS VPN environment.
Encoding of the NLRI is described in Section 4 for IPv4 Flow Encoding of the NLRI is described in Section 4 for IPv4 Flow
Specification and in Section 8 for VPNv4 Flow Specification. The Specification and in Section 8 for VPNv4 Flow Specification. The
filtering actions are described in Section 7. filtering actions are described in Section 7.
5.1. Ordering of Flow Specifications 5.1. Ordering of Flow Specifications
More than one Flow Specification may match a particular traffic flow. More than one Flow Specification may match a particular traffic flow.
skipping to change at page 17, line 37 skipping to change at line 843
on the arrival order of the Flow Specification via BGP and thus is on the arrival order of the Flow Specification via BGP and thus is
consistent in the network. consistent in the network.
The relative order of two Flow Specifications is determined by The relative order of two Flow Specifications is determined by
comparing their respective components. The algorithm starts by comparing their respective components. The algorithm starts by
comparing the left-most components (lowest component type value) of comparing the left-most components (lowest component type value) of
the Flow Specifications. If the types differ, the Flow Specification the Flow Specifications. If the types differ, the Flow Specification
with lowest numeric type value has higher precedence (and thus will with lowest numeric type value has higher precedence (and thus will
match before) than the Flow Specification that doesn't contain that match before) than the Flow Specification that doesn't contain that
component type. If the component types are the same, then a type- component type. If the component types are the same, then a type-
specific comparison is performed (see below). If the types are equal specific comparison is performed (see below). If the types are
the algorithm continues with the next component. equal, the algorithm continues with the next component.
For IP prefix values (IP destination or source prefix): If one of the For IP prefix values (IP destination or source prefix), if one of the
two prefixes to compare is a more specific prefix of the other, the two prefixes to compare is a more specific prefix of the other, the
more specific prefix has higher precedence. Otherwise the one with more specific prefix has higher precedence. Otherwise, the one with
the lowest IP value has higher precedence. the lowest IP value has higher precedence.
For all other component types, unless otherwise specified, the For all other component types, unless otherwise specified, the
comparison is performed by comparing the component data as a binary comparison is performed by comparing the component data as a binary
string using the memcmp() function as defined by [ISO_IEC_9899]. For string using the memcmp() function as defined by [ISO_IEC_9899]. For
strings with equal lengths the lowest string (memcmp) has higher strings with equal lengths, the lowest string (memcmp) has higher
precedence. For strings of different lengths, the common prefix is precedence. For strings of different lengths, the common prefix is
compared. If the common prefix is not equal the string with the compared. If the common prefix is not equal, the string with the
lowest prefix has higher precedence. If the common prefix is equal, lowest prefix has higher precedence. If the common prefix is equal,
the longest string is considered to have higher precedence than the the longest string is considered to have higher precedence than the
shorter one. shorter one.
The code in Appendix A shows a Python3 implementation of the The code in Appendix A shows a Python3 implementation of the
comparison algorithm. The full code was tested with Python 3.6.3 and comparison algorithm. The full code was tested with Python 3.6.3 and
can be obtained at can be obtained at
https://github.com/stoffi92/rfc5575bis/tree/master/flowspec-cmp [1]. <https://github.com/stoffi92/rfc5575bis/tree/master/flowspec-cmp>.
6. Validation Procedure 6. Validation Procedure
Flow Specifications received from a BGP peer that are accepted in the Flow Specifications received from a BGP peer that are accepted in the
respective Adj-RIB-In are used as input to the route selection respective Adj-RIB-In are used as input to the route selection
process. Although the forwarding attributes of two routes for the process. Although the forwarding attributes of two routes for the
same Flow Specification prefix may be the same, BGP is still required same Flow Specification prefix may be the same, BGP is still required
to perform its path selection algorithm in order to select the to perform its path selection algorithm in order to select the
correct set of attributes to advertise. correct set of attributes to advertise.
The first step of the BGP Route Selection procedure (Section 9.1.2 of The first step of the BGP Route Selection procedure (Section 9.1.2 of
[RFC4271] is to exclude from the selection procedure routes that are [RFC4271]) is to exclude from the selection procedure routes that are
considered non-feasible. In the context of IP routing information, considered unfeasible. In the context of IP routing information,
this step is used to validate that the NEXT_HOP attribute of a given this step is used to validate that the NEXT_HOP attribute of a given
route is resolvable. route is resolvable.
The concept can be extended, in the case of the Flow Specification The concept can be extended, in the case of the Flow Specification
NLRI, to allow other validation procedures. NLRI, to allow other validation procedures.
The validation process described below validates Flow Specifications The validation process described below validates Flow Specifications
against unicast routes received over the same AFI but the associated against unicast routes received over the same AFI but the associated
unicast routing information SAFI: unicast routing information SAFI:
Flow Specification received over SAFI=133 will be validated * Flow Specification received over SAFI=133 will be validated
against routes received over SAFI=1 against routes received over SAFI=1.
Flow Specification received over SAFI=134 will be validated * Flow Specification received over SAFI=134 will be validated
against routes received over SAFI=128 against routes received over SAFI=128.
In the absence of explicit configuration a Flow Specification NLRI In the absence of explicit configuration, a Flow Specification NLRI
MUST be validated such that it is considered feasible if and only if MUST be validated such that it is considered feasible if and only if
all of the conditions below are true: all of the conditions below are true:
a) A destination prefix component is embedded in the Flow a) A destination prefix component is embedded in the Flow
Specification. Specification.
b) The originator of the Flow Specification matches the originator b) The originator of the Flow Specification matches the originator
of the best-match unicast route for the destination prefix of the best-match unicast route for the destination prefix
embedded in the Flow Specification (this is the unicast route with embedded in the Flow Specification (this is the unicast route
the longest possible prefix length covering the destination prefix with the longest possible prefix length covering the destination
embedded in the Flow Specification). prefix embedded in the Flow Specification).
c) There are no "more-specific" unicast routes, when compared with c) There are no "more-specific" unicast routes, when compared with
the flow destination prefix, that have been received from a the flow destination prefix, that have been received from a
different neighboring AS than the best-match unicast route, which different neighboring AS than the best-match unicast route, which
has been determined in rule b). has been determined in rule b.
However, rule a) MAY be relaxed by explicit configuration, permitting However, rule a MAY be relaxed by explicit configuration, permitting
Flow Specifications that include no destination prefix component. If Flow Specifications that include no destination prefix component. If
such is the case, rules b) and c) are moot and MUST be disregarded. such is the case, rules b and c are moot and MUST be disregarded.
By "originator" of a BGP route, we mean either the address of the By "originator" of a BGP route, we mean either the address of the
originator in the ORIGINATOR_ID Attribute [RFC4456], or the source IP originator in the ORIGINATOR_ID Attribute [RFC4456] or the source IP
address of the BGP peer, if this path attribute is not present. address of the BGP peer, if this path attribute is not present.
BGP implementations MUST also enforce that the AS_PATH attribute of a BGP implementations MUST also enforce that the AS_PATH attribute of a
route received via the External Border Gateway Protocol (eBGP) route received via the External Border Gateway Protocol (eBGP)
contains the neighboring AS in the left-most position of the AS_PATH contains the neighboring AS in the left-most position of the AS_PATH
attribute. While this rule is optional in the BGP specification, it attribute. While this rule is optional in the BGP specification, it
becomes necessary to enforce it here for security reasons. becomes necessary to enforce it here for security reasons.
The best-match unicast route may change over the time independently The best-match unicast route may change over the time independently
of the Flow Specification NLRI. Therefore, a revalidation of the of the Flow Specification NLRI. Therefore, a revalidation of the
Flow Specification NLRI MUST be performed whenever unicast routes Flow Specification NLRI MUST be performed whenever unicast routes
change. Revalidation is defined as retesting rules a) to c) as change. Revalidation is defined as retesting rules a to c as
described above. described above.
Explanation: Explanation:
The underlying concept is that the neighboring AS that advertises the The underlying concept is that the neighboring AS that advertises the
best unicast route for a destination is allowed to advertise Flow best unicast route for a destination is allowed to advertise Flow
Specification information that conveys a destination prefix that is Specification information that conveys a destination prefix that is
more or equally specific. Thus, as long as there are no "more- more or equally specific. Thus, as long as there are no "more-
specific" unicast routes, received from a different neighboring AS, specific" unicast routes received from a different neighboring AS,
which would be affected by that Flow Specification, the Flow which would be affected by that Flow Specification, the Flow
Specification is validated successfully. Specification is validated successfully.
The neighboring AS is the immediate destination of the traffic The neighboring AS is the immediate destination of the traffic
described by the Flow Specification. If it requests these flows to described by the Flow Specification. If it requests these flows to
be dropped, that request can be honored without concern that it be dropped, that request can be honored without concern that it
represents a denial of service in itself. The reasoning is that this represents a denial of service in itself. The reasoning is that this
is as if the traffic is being dropped by the downstream autonomous is as if the traffic is being dropped by the downstream autonomous
system, and there is no added value in carrying the traffic to it. system, and there is no added value in carrying the traffic to it.
7. Traffic Filtering Actions 7. Traffic Filtering Actions
This document defines a minimum set of Traffic Filtering Actions that This document defines a minimum set of Traffic Filtering Actions that
it standardizes as BGP extended communities [RFC4360]. This is not it standardizes as BGP Extended Communities [RFC4360]. This is not
meant to be an inclusive list of all the possible actions, but only a meant to be an inclusive list of all the possible actions but only a
subset that can be interpreted consistently across the network. subset that can be interpreted consistently across the network.
Additional actions can be defined as either requiring standards or as Additional actions can be defined as either requiring standards or as
vendor specific. vendor specific.
The default action for a matching Flow Specification is to accept the The default action for a matching Flow Specification is to accept the
packet (treat the packet according to the normal forwarding behaviour packet (treat the packet according to the normal forwarding behavior
of the system). of the system).
This document defines the following extended communities values shown This document defines the following Extended Communities values shown
in Table 2 in the form 0xttss where tt indicates the type and ss in Table 8 in the form 0xttss, where tt indicates the type and ss
indicates the sub-type of the extended community. Encodings for indicates the sub-type of the Extended Community. Encodings for
these extended communities are described below. these Extended Communities are described below.
+-------------+---------------------------+-------------------------+ +==================+======================+=======================+
| community | action | encoding | | community 0xttss | action | encoding |
| 0xttss | | | +==================+======================+=======================+
+-------------+---------------------------+-------------------------+ | 0x8006 | traffic-rate-bytes | 2-octet AS, 4-octet |
| 0x8006 | traffic-rate-bytes | 2-octet AS, 4-octet | | | (Section 7.1) | float |
| | (Section 7.1) | float | +------------------+----------------------+-----------------------+
| TBD | traffic-rate-packets | 2-octet AS, 4-octet | | 0x800c | traffic-rate-packets | 2-octet AS, 4-octet |
| | (Section 7.1) | float | | | (Section 7.2) | float |
| 0x8007 | traffic-action | bitmask | +------------------+----------------------+-----------------------+
| | (Section 7.3) | | | 0x8007 | traffic-action | bitmask |
| 0x8008 | rt-redirect AS-2octet | 2-octet AS, 4-octet | | | (Section 7.3) | |
| | (Section 7.4) | value | +------------------+----------------------+-----------------------+
| 0x8108 | rt-redirect IPv4 | 4-octet IPv4 address, | | 0x8008 | rt-redirect AS- | 2-octet AS, 4-octet |
| | (Section 7.4) | 2-octet value | | | 2octet (Section 7.4) | value |
| 0x8208 | rt-redirect AS-4octet | 4-octet AS, 2-octet | +------------------+----------------------+-----------------------+
| | (Section 7.4) | value | | 0x8108 | rt-redirect IPv4 | 4-octet IPv4 address, |
| 0x8009 | traffic-marking | DSCP value | | | (Section 7.4) | 2-octet value |
| | (Section 7.5) | | +------------------+----------------------+-----------------------+
+-------------+---------------------------+-------------------------+ | 0x8208 | rt-redirect AS- | 4-octet AS, 2-octet |
| | 4octet (Section 7.4) | value |
+------------------+----------------------+-----------------------+
| 0x8009 | traffic-marking | DSCP value |
| | (Section 7.5) | |
+------------------+----------------------+-----------------------+
Table 2: Traffic Filtering Action Extended Communities Table 8: Traffic Filtering Action Extended Communities
Multiple Traffic Filtering Actions defined in this document may be Multiple Traffic Filtering Actions defined in this document may be
present for a single Flow Specification and SHOULD be applied to the present for a single Flow Specification and SHOULD be applied to the
traffic flow (for example traffic-rate-bytes and rt-redirect can be traffic flow (for example, traffic-rate-bytes and rt-redirect can be
applied to packets at the same time). If not all of the Traffic applied to packets at the same time). If not all of the Traffic
Filtering Actions can be applied to a traffic flow they should be Filtering Actions can be applied to a traffic flow, they should be
treated as interfering Traffic Filtering Actions (see below). treated as interfering Traffic Filtering Actions (see below).
Some Traffic Filtering Actions may interfere with each other or even Some Traffic Filtering Actions may interfere with each other or even
contradict. Section 7.7 of this document provides general contradict. Section 7.7 of this document provides general
considerations on such Traffic Filtering Action interference. Any considerations on such Traffic Filtering Action interference. Any
additional definition of Traffic Filtering Actions SHOULD specify the additional definition of Traffic Filtering Actions SHOULD specify the
action to take if those Traffic Filtering Actions interfere (also action to take if those Traffic Filtering Actions interfere (also
with existing Traffic Filtering Actions). with existing Traffic Filtering Actions).
All Traffic Filtering Actions are specified as transitive BGP All Traffic Filtering Actions are specified as transitive BGP
Extended Communities. Extended Communities.
7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 7.1. Traffic Rate in Bytes (traffic-rate-bytes) Sub-Type 0x06
The traffic-rate-bytes extended community uses the following extended The traffic-rate-bytes Extended Community uses the following Extended
community encoding: Community encoding:
The first two octets carry the 2-octet id, which can be assigned from The first two octets carry the 2-octet id, which can be assigned from
a 2-octet AS number. When a 4-octet AS number is locally present, a 2-octet AS number. When a 4-octet AS number is locally present,
the 2 least significant octets of such an AS number can be used. the 2 least significant octets of such an AS number can be used.
This value is purely informational and SHOULD NOT be interpreted by This value is purely informational and SHOULD NOT be interpreted by
the implementation. the implementation.
The remaining 4 octets carry the maximum rate information in IEEE The remaining 4 octets carry the maximum rate information in IEEE
floating point [IEEE.754.1985] format, units being bytes per second. floating point [IEEE.754.1985] format, units being bytes per second.
A traffic-rate of 0 should result on all traffic for the particular A traffic-rate of 0 should result on all traffic for the particular
flow to be discarded. On encoding the traffic-rate MUST NOT be flow to be discarded. On encoding, the traffic-rate MUST NOT be
negative. On decoding negative values MUST be treated as zero negative. On decoding, negative values MUST be treated as zero
(discard all traffic). (discard all traffic).
Interferes with: May interfere with the traffic-rate-packets (see Interferes with: May interfere with the traffic-rate-packets (see
Section 7.2). A policy may allow both filtering by traffic-rate- Section 7.2). A policy may allow both filtering by traffic-rate-
packets and traffic-rate-bytes. If the policy does not allow this, packets and traffic-rate-bytes. If the policy does not allow this,
these two actions will conflict. these two actions will conflict.
7.2. Traffic Rate in Packets (traffic-rate-packets) sub-type TBD 7.2. Traffic Rate in Packets (traffic-rate-packets) Sub-Type 0x0c
The traffic-rate-packets extended community uses the same encoding as The traffic-rate-packets Extended Community uses the same encoding as
the traffic-rate-bytes extended community. The floating point value the traffic-rate-bytes Extended Community. The floating point value
carries the maximum packet rate in packets per second. A traffic- carries the maximum packet rate in packets per second. A traffic-
rate-packets of 0 should result in all traffic for the particular rate-packets of 0 should result in all traffic for the particular
flow to be discarded. On encoding the traffic-rate-packets MUST NOT flow to be discarded. On encoding, the traffic-rate-packets MUST NOT
be negative. On decoding negative values MUST be treated as zero be negative. On decoding, negative values MUST be treated as zero
(discard all traffic). (discard all traffic).
Interferes with: May interfere with the traffic-rate-bytes (see Interferes with: May interfere with the traffic-rate-bytes (see
Section 7.1). A policy may allow both filtering by traffic-rate- Section 7.1). A policy may allow both filtering by traffic-rate-
packets and traffic-rate-bytes. If the policy does not allow this, packets and traffic-rate-bytes. If the policy does not allow this,
these two actions will conflict. these two actions will conflict.
7.3. Traffic-action (traffic-action) sub-type 0x07 7.3. Traffic-Action (traffic-action) Sub-Type 0x07
The traffic-action extended community consists of 6 octets of which The traffic-action Extended Community consists of 6 octets of which
only the 2 least significant bits of the 6th octet (from left to only the 2 least significant bits of the 6th octet (from left to
right) are defined by this document as shown in Figure 5. right) are defined by this document, as shown in Figure 5.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Action Field | | Traffic Action Field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tr. Action Field (cont.) |S|T| | Tr. Action Field (cont.) |S|T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Traffic-action Extended Community Encoding Figure 5: Traffic-Action Extended Community Encoding
where S and T are defined as: S and T are defined as:
o T: Terminal Action (bit 47): When this bit is set, the traffic T Terminal Action (bit 47): When this bit is set, the traffic
filtering engine will evaluate any subsequent Flow Specifications filtering engine will evaluate any subsequent Flow
(as defined by the ordering procedure Section 5.1). If not set, Specifications (as defined by the ordering procedure
the evaluation of the traffic filters stops when this Flow Section 5.1). If not set, the evaluation of the traffic
Specification is evaluated. filters stops when this Flow Specification is evaluated.
o S: Sample (bit 46): Enables traffic sampling and logging for this S Sample (bit 46): Enables traffic sampling and logging for this
Flow Specification (only effective when set). Flow Specification (only effective when set).
o Traffic Action Field: Other Traffic Action Field (see Section 11) Traffic Action Field: Other Traffic Action Field (see Section 11)
bits unused in this specification. These bits MUST be set to 0 on bits unused in this specification. These bits MUST be set to 0
encoding, and MUST be ignored during decoding. on encoding and MUST be ignored during decoding.
The use of the Terminal Action (bit 47) may result in more than one The use of the Terminal Action (bit 47) may result in more than one
Flow Specification matching a particular traffic flow. All the Flow Specification matching a particular traffic flow. All the
Traffic Filtering Actions from these Flow Specifications shall be Traffic Filtering Actions from these Flow Specifications shall be
collected and applied. In case of interfering Traffic Filtering collected and applied. In case of interfering Traffic Filtering
Actions it is an implementation decision which Traffic Filtering Actions, it is an implementation decision which Traffic Filtering
Actions are selected. See also Section 7.7. Actions are selected. See also Section 7.7.
Interferes with: No other BGP Flow Specification Traffic Filtering Interferes with: No other BGP Flow Specification Traffic Filtering
Action in this document. Action in this document.
7.4. RT Redirect (rt-redirect) sub-type 0x08 7.4. RT Redirect (rt-redirect) Sub-Type 0x08
The redirect extended community allows the traffic to be redirected The redirect Extended Community allows the traffic to be redirected
to a VRF routing instance that lists the specified route-target in to a VRF routing instance that lists the specified route-target in
its import policy. If several local instances match this criteria, its import policy. If several local instances match this criteria,
the choice between them is a local matter (for example, the instance the choice between them is a local matter (for example, the instance
with the lowest Route Distinguisher value can be elected). with the lowest Route Distinguisher value can be elected).
This Extended Community allows 3 different encodings formats for the This Extended Community allows 3 different encodings formats for the
route-target (type 0x80, 0x81, 0x82). It uses the same encoding as route-target (type 0x80, 0x81, 0x82). It uses the same encoding as
the Route Target Extended Community in Sections 3.1 (type 0x80: the Route Target Extended Community in Sections 3.1 (type 0x80:
2-octet AS, 4-octet value), 3.2 (type 0x81: 4-octet IPv4 address, 2-octet AS, 4-octet value), 3.2 (type 0x81: 4-octet IPv4 address,
2-octet value) and 4 of [RFC4360] and Section 2 (type 0x82: 4-octet 2-octet value), and 4 of [RFC4360] and Section 2 of [RFC5668] (type
AS, 2-octet value) of [RFC5668] with the high-order octet of the Type 0x82: 4-octet AS, 2-octet value) with the high-order octet of the
field 0x80, 0x81, 0x82 respectively and the low-order of the Type Type field 0x80, 0x81, 0x82 respectively and the low-order octet of
field (Sub-Type) always 0x08. the Type field (Sub-Type) always 0x08.
Interferes with: No other BGP Flow Specification Traffic Filtering Interferes with: No other BGP Flow Specification Traffic Filtering
Action in this document. Action in this document.
7.5. Traffic Marking (traffic-marking) sub-type 0x09 7.5. Traffic Marking (traffic-marking) Sub-Type 0x09
The traffic marking extended community instructs a system to modify The traffic marking Extended Community instructs a system to modify
the DSCP bits in the IP header ([RFC2474] Section 3) of a transiting the DSCP bits in the IP header (Section 3 of [RFC2474]) of a
IP packet to the corresponding value encoded in the 6 least transiting IP packet to the corresponding value encoded in the 6
significant bits of the extended community value as shown in least significant bits of the Extended Community value, as shown in
Figure 6. Figure 6.
The extended is encoded as follows: The Extended Community is encoded as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| reserved | reserved | reserved | reserved | | reserved | reserved | reserved | reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| reserved | r.| DSCP | | reserved | r.| DSCP |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Traffic Marking Extended Community Encoding Figure 6: Traffic Marking Extended Community Encoding
o DSCP: new DSCP value for the transiting IP packet. DSCP: new DSCP value for the transiting IP packet
o reserved, r.: MUST be set to 0 on encoding, and MUST be ignored reserved (r): MUST be set to 0 on encoding and MUST be ignored
during decoding. during decoding
Interferes with: No other BGP Flow Specification Traffic Filtering Interferes with: No other BGP Flow Specification Traffic Filtering
Action in this document. Action in this document.
7.6. Interaction with other Filtering Mechanisms in Routers 7.6. Interaction with Other Filtering Mechanisms in Routers
Implementations should provide mechanisms that map an arbitrary BGP Implementations should provide mechanisms that map an arbitrary BGP
community value (normal or extended) to Traffic Filtering Actions community value (normal or extended) to Traffic Filtering Actions
that require different mappings on different systems in the network. that require different mappings on different systems in the network.
For instance, providing packets with a worse-than-best-effort per-hop For instance, providing packets with a worse-than-best-effort per-hop
behavior is a functionality that is likely to be implemented behavior is a functionality that is likely to be implemented
differently in different systems and for which no standard behavior differently in different systems and for which no standard behavior
is currently known. Rather than attempting to define it here, this is currently known. Rather than attempting to define it here, this
can be accomplished by mapping a user-defined community value to can be accomplished by mapping a user-defined community value to
platform-/network-specific behavior via user configuration. platform-/network-specific behavior via user configuration.
7.7. Considerations on Traffic Filtering Action Interference 7.7. Considerations on Traffic Filtering Action Interference
Since Traffic Filtering Actions are represented as BGP extended Since Traffic Filtering Actions are represented as BGP extended
community values, Traffic Filtering Actions may interfere with each community values, Traffic Filtering Actions may interfere with each
other (e.g. there may be more than one conflicting traffic-rate-bytes other (e.g., there may be more than one conflicting traffic-rate-
Traffic Filtering Action associated with a single Flow bytes Traffic Filtering Action associated with a single Flow
Specification). Traffic Filtering Action interference has no impact Specification). Traffic Filtering Action interference has no impact
on BGP propagation of Flow Specifications (all communities are on BGP propagation of Flow Specifications (all communities are
propagated according to policies). propagated according to policies).
If a Flow Specification associated with interfering Traffic Filtering If a Flow Specification associated with interfering Traffic Filtering
Actions is selected for packet forwarding, it is an implementation Actions is selected for packet forwarding, it is an implementation
decision which of the interfering Traffic Filtering Actions are decision which of the interfering Traffic Filtering Actions are
selected. Implementors of this specification SHOULD document the selected. Implementors of this specification SHOULD document the
behaviour of their implementation in such cases. behavior of their implementation in such cases.
Operators are encouraged to make use of the BGP policy framework Operators are encouraged to make use of the BGP policy framework
supported by their implementation in order to achieve a predictable supported by their implementation in order to achieve a predictable
behaviour. See also Section 12. behavior. See also Section 12.
8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks 8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks
Provider-based Layer 3 VPN networks, such as the ones using a BGP/ Provider-based Layer 3 VPN networks, such as the ones using a BGP/
MPLS IP VPN [RFC4364] control plane, may have different traffic MPLS IP VPN [RFC4364] control plane, may have different traffic
filtering requirements than Internet service providers. But also filtering requirements than Internet service providers. But also
Internet service providers may use those VPNs for scenarios like Internet service providers may use those VPNs for scenarios like
having the Internet routing table in a VRF, resulting in the same having the Internet routing table in a VRF, resulting in the same
traffic filtering requirements as defined for the global routing traffic filtering requirements as defined for the global routing
table environment within this document. This document defines an table environment within this document. This document defines an
skipping to change at page 24, line 45 skipping to change at line 1190
to propagate Flow Specification in a BGP/MPLS VPN environment. to propagate Flow Specification in a BGP/MPLS VPN environment.
The NLRI format for this address family consists of a fixed-length The NLRI format for this address family consists of a fixed-length
Route Distinguisher field (8 octets) followed by the Flow Route Distinguisher field (8 octets) followed by the Flow
Specification NLRI value (Section 4.2). The NLRI length field shall Specification NLRI value (Section 4.2). The NLRI length field shall
include both the 8 octets of the Route Distinguisher as well as the include both the 8 octets of the Route Distinguisher as well as the
subsequent Flow Specification NLRI value. The resulting encoding is subsequent Flow Specification NLRI value. The resulting encoding is
shown in Figure 7. shown in Figure 7.
+--------------------------------+ +--------------------------------+
| length (0xnn or 0xfn nn) | | length (0xnn or 0xfnnn) |
+--------------------------------+ +--------------------------------+
| Route Distinguisher (8 octets) | | Route Distinguisher (8 octets) |
+--------------------------------+ +--------------------------------+
| NLRI value (variable) | | NLRI value (variable) |
+--------------------------------+ +--------------------------------+
Figure 7: Flow Specification NLRI for MPLS Figure 7: Flow Specification NLRI for MPLS
Propagation of this NLRI is controlled by matching Route Target Propagation of this NLRI is controlled by matching Route Target
extended communities associated with the BGP path advertisement with extended communities associated with the BGP path advertisement with
the VRF import policy, using the same mechanism as described in BGP/ the VRF import policy, using the same mechanism as described in BGP/
MPLS IP VPNs [RFC4364]. MPLS IP VPNs [RFC4364].
Flow Specifications received via this NLRI apply only to traffic that Flow Specifications received via this NLRI apply only to traffic that
belongs to the VRF(s) in which it is imported. By default, traffic belongs to the VRF(s) in which it is imported. By default, traffic
received from a remote PE is switched via an MPLS forwarding decision received from a remote PE is switched via an MPLS forwarding decision
and is not subject to filtering. and is not subject to filtering.
skipping to change at page 25, line 28 skipping to change at line 1222
The validation procedure (Section 6) and Traffic Filtering Actions The validation procedure (Section 6) and Traffic Filtering Actions
(Section 7) are the same as for IPv4. (Section 7) are the same as for IPv4.
9. Traffic Monitoring 9. Traffic Monitoring
Traffic filtering applications require monitoring and traffic Traffic filtering applications require monitoring and traffic
statistics facilities. While this is an implementation specific statistics facilities. While this is an implementation specific
choice, implementations SHOULD provide: choice, implementations SHOULD provide:
o A mechanism to log the packet header of filtered traffic. * A mechanism to log the packet header of filtered traffic.
o A mechanism to count the number of matches for a given Flow * A mechanism to count the number of matches for a given Flow
Specification. Specification rule.
10. Error Handling 10. Error Handling
Error handling according to [RFC7606] and [RFC4760] applies to this Error handling according to [RFC7606] and [RFC4760] applies to this
specification. specification.
This document introduces Traffic Filtering Action Extended This document introduces Traffic Filtering Action Extended
Communities. Malformed Traffic Filtering Action Extended Communities Communities. Malformed Traffic Filtering Action Extended Communities
in the sense of [RFC7606] Section 7.14. are Extended Community values in the sense of Section 7.14 of [RFC7606] are Extended Community
that cannot be decoded according to Section 7 of this document. values that cannot be decoded according to Section 7 of this
document.
11. IANA Considerations 11. IANA Considerations
This section complies with [RFC7153]. This section complies with [RFC7153].
11.1. AFI/SAFI Definitions 11.1. AFI/SAFI Definitions
IANA maintains a registry entitled "SAFI Values". For the purpose of IANA maintains a registry entitled "SAFI Values". For the purpose of
this work, IANA is requested to update the following SAFIs to read this work, IANA has updated the following SAFIs as shown in the table
according to the table below (Note: This document obsoletes both below. (Note: This document obsoletes both [RFC7674] and [RFC5575],
RFC7674 and RFC5575 and all references to those documents should be and all references to those documents have been deleted from the
deleted from the registry below): registry.)
+-------+------------------------------------------+----------------+ +=======+===========================================+===========+
| Value | Name | Reference | | Value | Name | Reference |
+-------+------------------------------------------+----------------+ +=======+===========================================+===========+
| 133 | Dissemination of Flow Specification | [this | | 133 | Dissemination of Flow Specification rules | RFC 8955 |
| | rules | document] | +-------+-------------------------------------------+-----------+
| 134 | L3VPN Dissemination of Flow | [this | | 134 | L3VPN Dissemination of Flow Specification | RFC 8955 |
| | Specification rules | document] | | | rules | |
+-------+------------------------------------------+----------------+ +-------+-------------------------------------------+-----------+
Table 3: Registry: SAFI Values Table 9: Registry: SAFI Values
The above textual changes generalise the definition of the SAFIs The above textual changes generalize the definition of the SAFIs
rather than change its underlying meaning. Therefore, based on rather than change its underlying meaning. Therefore, based on "The
"The YANG 1.1 Data Modeling Language" [RFC7950], the above text YANG 1.1 Data Modeling Language" [RFC7950], the above text means that
implies that the following YANG enums from the following YANG enums from "Common YANG Data Types for the Routing
"Common YANG Data Types for the Routing Area" [RFC8294] need to have Area" [RFC8294] have had their names and descriptions at
their names and descriptions at https://www.iana.org/assignments/ <https://www.iana.org/assignments/iana-routing-types> changed to:
iana-routing-types [2] changed to:
<CODE BEGINS> <CODE BEGINS>
enum flow-spec-safi { enum flow-spec-safi {
value 133; value 133;
description description
"Dissemination of Flow Specification rules SAFI."; "Dissemination of Flow Specification rules SAFI.";
} }
enum l3vpn-flow-spec-safi { enum l3vpn-flow-spec-safi {
value 134; value 134;
description description
"L3VPN Dissemination of Flow Specification rules SAFI."; "L3VPN Dissemination of Flow Specification rules SAFI.";
} }
<CODE ENDS> <CODE ENDS>
A new revision statement should be added to the module as follows: A new revision statement has been added to the module as follows:
<CODE BEGINS> <CODE BEGINS>
revision [revision date] { revision 2020-12-31 {
description "Non-backwards-compatible change of SAFI names description "Non-backwards-compatible change of SAFI names
(SAFI values 133, 134)."; (SAFI values 133, 134).";
reference reference
"[this document]: Dissemination of Flow Specification Rules."; "RFC 8955: Dissemination of Flow Specification Rules.";
} }
<CODE ENDS> <CODE ENDS>
11.2. Flow Component Definitions 11.2. Flow Component Definitions
A Flow Specification consists of a sequence of flow components, which A Flow Specification consists of a sequence of flow components, which
are identified by an 8-bit component type. IANA has created and are identified by an 8-bit component type. IANA has created and
maintains a registry entitled "Flow Spec Component Types". IANA is maintains a registry entitled "Flow Spec Component Types". IANA has
requested to update the reference for this registry to [this updated the reference for this registry to RFC 8955. Furthermore,
document]. Furthermore the references to the values should be the references to the values have been updated according to the table
updated according to the table below (Note: This document obsoletes below (Note: This document obsoletes both [RFC7674] and [RFC5575],
both RFC7674 and RFC5575 and all references to those documents should and all references to those documents have been deleted from the
be deleted from the registry below). registry.)
+-------+--------------------+-----------------+ +=======+====================+===========+
| Value | Name | Reference | | Value | Name | Reference |
+-------+--------------------+-----------------+ +=======+====================+===========+
| 1 | Destination Prefix | [this document] | | 1 | Destination Prefix | RFC 8955 |
| 2 | Source Prefix | [this document] | +-------+--------------------+-----------+
| 3 | IP Protocol | [this document] | | 2 | Source Prefix | RFC 8955 |
| 4 | Port | [this document] | +-------+--------------------+-----------+
| 5 | Destination port | [this document] | | 3 | IP Protocol | RFC 8955 |
| 6 | Source port | [this document] | +-------+--------------------+-----------+
| 7 | ICMP type | [this document] | | 4 | Port | RFC 8955 |
| 8 | ICMP code | [this document] | +-------+--------------------+-----------+
| 9 | TCP flags | [this document] | | 5 | Destination port | RFC 8955 |
| 10 | Packet length | [this document] | +-------+--------------------+-----------+
| 11 | DSCP | [this document] | | 6 | Source port | RFC 8955 |
| 12 | Fragment | [this document] | +-------+--------------------+-----------+
+-------+--------------------+-----------------+ | 7 | ICMP type | RFC 8955 |
+-------+--------------------+-----------+
| 8 | ICMP code | RFC 8955 |
+-------+--------------------+-----------+
| 9 | TCP flags | RFC 8955 |
+-------+--------------------+-----------+
| 10 | Packet length | RFC 8955 |
+-------+--------------------+-----------+
| 11 | DSCP | RFC 8955 |
+-------+--------------------+-----------+
| 12 | Fragment | RFC 8955 |
+-------+--------------------+-----------+
Table 4: Registry: Flow Spec Component Types Table 10: Registry: Flow Spec
Component Types
In order to manage the limited number space and accommodate several In order to manage the limited number space and accommodate several
usages, the following policies defined by [RFC8126] are used: usages, the following policies defined by [RFC8126] are used:
+--------------+------------------------+ +==============+========================+
| Type Values | Policy | | Type Values | Policy |
+--------------+------------------------+ +==============+========================+
| 0 | Reserved | | 0 | Reserved |
+--------------+------------------------+
| [1 .. 127] | Specification Required | | [1 .. 127] | Specification Required |
+--------------+------------------------+
| [128 .. 254] | Expert Review | | [128 .. 254] | Expert Review |
+--------------+------------------------+
| 255 | Reserved | | 255 | Reserved |
+--------------+------------------------+ +--------------+------------------------+
Table 5: Flow Spec Component Types Policies Table 11: Flow Spec Component Types
Policies
Guidance for Experts: Guidance for Experts:
128-254 requires Expert Review as the registration policy. The The registration policy for the range 128-254 is Expert Review.
Experts are expected to check the clarity of purpose and use of The experts are expected to check the clarity of purpose and use
the requested code points. The Experts must also verify that of the requested code points. The experts must also verify that
any specification produced in the IETF that requests one of any specification produced in the IETF that requests one of these
these code points has been made available for review by the IDR code points has been made available for review by the IDR Working
working group and that any specification produced outside the Group and that any specification produced outside the IETF does
IETF does not conflict with work that is active or already not conflict with work that is active or already published within
published within the IETF. It must be pointed out that the IETF. It must be pointed out that introducing new component
introducing new component types may break interoperability with types may break interoperability with existing implementations of
existing implementations of this protocol. this protocol.
11.3. Extended Community Flow Specification Actions 11.3. Extended Community Flow Specification Actions
The Extended Community Flow Specification Action types defined in The Extended Community Flow Specification Action types defined in
this document consist of two parts: this document consist of two parts:
Type (BGP Transitive Extended Community Type) * Type (BGP Transitive Extended Community Type)
Sub-Type * Sub-Type
For the type-part, IANA maintains a registry entitled "BGP Transitive For the type part, IANA maintains a registry entitled "BGP Transitive
Extended Community Types". For the purpose of this work (Section 7), Extended Community Types". For the purpose of this work (Section 7),
IANA is requested to update the references to the following entries IANA has updated the references as shown in the table below. (Note:
according to the table below (Note: This document obsoletes both This document obsoletes both [RFC7674] and [RFC5575], and all
RFC7674 and RFC5575 and all references to those documents should be references to those documents have been deleted in the registry.)
deleted in the registry below):
+-------+-----------------------------------------------+-----------+ +=======+=======================================+===========+
| Type | Name | Reference | | Type | Name | Reference |
| Value | | | | Value | | |
+-------+-----------------------------------------------+-----------+ +=======+=======================================+===========+
| 0x81 | Generic Transitive Experimental | [this | | 0x81 | Generic Transitive Experimental Use | RFC 8955 |
| | Use Extended Community Part 2 (Sub-Types are | document] | | | Extended Community Part 2 (Sub-Types | |
| | defined in the "Generic Transitive | | | | are defined in the "Generic | |
| | Experimental Use Extended Community Part 2 | | | | Transitive Experimental Use Extended | |
| | Sub-Types" Registry) | | | | Community Part 2 Sub-Types" Registry) | |
| 0x82 | Generic Transitive Experimental | [this | +-------+---------------------------------------+-----------+
| | Use Extended Community Part 3 | document] | | 0x82 | Generic Transitive Experimental Use | RFC 8955 |
| | (Sub-Types are defined in the "Generic | | | | Extended Community Part 3 (Sub-Types | |
| | Transitive Experimental Use | | | | are defined in the "Generic | |
| | Extended Community Part 3 Sub-Types" | | | | Transitive Experimental Use Extended | |
| | Registry) | | | | Community Part 3 Sub-Types" Registry) | |
+-------+-----------------------------------------------+-----------+ +-------+---------------------------------------+-----------+
Table 6: Registry: BGP Transitive Extended Community Types Table 12: Registry: BGP Transitive Extended Community Types
For the sub-type part of the extended community Traffic Filtering For the sub-type part of the Extended Community Traffic Filtering
Actions IANA maintains the following registries. IANA is requested Actions, IANA maintains the following registries. IANA has updated
to update all names and references according to the tables below and all names and references according to the tables below and assign a
assign a new value for the "Flow spec traffic-rate-packets" Sub-Type new value for the "Flow spec traffic-rate-packets" Sub-Type. (Note:
(Note: This document obsoletes both RFC7674 and RFC5575 and all This document obsoletes both [RFC7674] and [RFC5575], and all
references to those documents should be deleted from the registries references to those documents have been deleted from the registries
below). below.)
+----------+--------------------------------------------+-----------+ +==========+=====================================+===========+
| Sub-Type | Name | Reference | | Sub-Type | Name | Reference |
| Value | | | | Value | | |
+----------+--------------------------------------------+-----------+ +==========+=====================================+===========+
| 0x06 | Flow spec traffic-rate-bytes | [this | | 0x06 | Flow spec traffic-rate-bytes | RFC 8955 |
| | | document] | +----------+-------------------------------------+-----------+
| TBD | Flow spec traffic-rate-packets | [this | | 0x0c | Flow spec traffic-rate-packets | RFC 8955 |
| | | document] | +----------+-------------------------------------+-----------+
| 0x07 | Flow spec traffic-action (Use | [this | | 0x07 | Flow spec traffic-action (Use of | RFC 8955 |
| | of the "Value" field is defined in the | document] | | | the "Value" field is defined in the | |
| | "Traffic Action Fields" registry) | | | | "Traffic Action Fields" registry) | |
| 0x08 | Flow spec rt-redirect | [this | +----------+-------------------------------------+-----------+
| | AS-2octet format | document] | | 0x08 | Flow spec rt-redirect AS-2octet | RFC 8955 |
| 0x09 | Flow spec traffic-remarking | [this | | | format | |
| | | document] | +----------+-------------------------------------+-----------+
+----------+--------------------------------------------+-----------+ | 0x09 | Flow spec traffic-remarking | RFC 8955 |
+----------+-------------------------------------+-----------+
Table 7: Registry: Generic Transitive Experimental Use Extended Table 13: Registry: Generic Transitive Experimental Use
Community Sub-Types Extended Community Sub- Types
+------------+----------------------------------------+-------------+ +================+===================================+===========+
| Sub-Type | Name | Reference | | Sub-Type Value | Name | Reference |
| Value | | | +================+===================================+===========+
+------------+----------------------------------------+-------------+ | 0x08 | Flow spec rt-redirect IPv4 format | RFC 8955 |
| 0x08 | Flow spec rt-redirect IPv4 | [this | +----------------+-----------------------------------+-----------+
| | format | document] |
+------------+----------------------------------------+-------------+
Table 8: Registry: Generic Transitive Experimental Use Extended Table 14: Registry: Generic Transitive Experimental Use
Community Part 2 Sub-Types Extended Community Part 2 Sub-Types
+------------+-----------------------------------------+------------+ +================+=======================+===========+
| Sub-Type | Name | Reference | | Sub-Type Value | Name | Reference |
| Value | | | +================+=======================+===========+
+------------+-----------------------------------------+------------+ | 0x08 | Flow spec rt-redirect | RFC 8955 |
| 0x08 | Flow spec rt-redirect | [this | | | AS-4octet format | |
| | AS-4octet format | document] | +----------------+-----------------------+-----------+
+------------+-----------------------------------------+------------+
Table 9: Registry: Generic Transitive Experimental Use Extended Table 15: Registry: Generic Transitive
Community Part 3 Sub-Types Experimental Use Extended Community Part 3 Sub-
Types
Furthermore IANA is requested to update the reference for the Furthermore, IANA has updated the reference for the registries
registries "Generic Transitive Experimental Use Extended Community "Generic Transitive Experimental Use Extended Community Part 2 Sub-
Part 2 Sub-Types" and "Generic Transitive Experimental Use Extended Types" and "Generic Transitive Experimental Use Extended Community
Community Part 3 Sub-Types" to [this document]. Part 3 Sub-Types" to RFC 8955.
The "traffic-action" extended community (Section 7.3) defined in this The "traffic-action" Extended Community (Section 7.3) defined in this
document has 46 unused bits, which can be used to convey additional document has 46 unused bits, which can be used to convey additional
meaning. IANA created and maintains a registry entitled: "Traffic meaning. IANA created and maintains a registry entitled "Traffic
Action Fields". IANA is requested to update the reference for this Action Fields". IANA has updated the reference for this registry to
registry to [this document]. Furthermore IANA is requested to update RFC 8955. Furthermore, IANA has updated the references according to
the references according to the table below. These values should be the table below. These values should be assigned via IETF Review
assigned via IETF Review rules only (Note: This document obsoletes rules only. (Note: This document obsoletes both [RFC7674] and
both RFC7674 and RFC5575 and all references to those documents should [RFC5575], and all references to those documents have been deleted
be deleted from the registry below). from the registry.)
+-----+-----------------+-----------------+ +=====+=================+===========+
| Bit | Name | Reference | | Bit | Name | Reference |
+-----+-----------------+-----------------+ +=====+=================+===========+
| 47 | Terminal Action | [this document] | | 47 | Terminal Action | RFC 8955 |
| 46 | Sample | [this document] | +-----+-----------------+-----------+
+-----+-----------------+-----------------+ | 46 | Sample | RFC 8955 |
+-----+-----------------+-----------+
Table 10: Registry: Traffic Action Fields Table 16: Registry: Traffic
Action Fields
12. Security Considerations 12. Security Considerations
As long as Flow Specifications are restricted to match the As long as Flow Specifications are restricted to match the
corresponding unicast routing paths for the relevant prefixes corresponding unicast routing paths for the relevant prefixes
(Section 6), the security characteristics of this proposal are (Section 6), the security characteristics of this proposal are
equivalent to the existing security properties of BGP unicast equivalent to the existing security properties of BGP unicast
routing. Any relaxation of the validation procedure described in routing. Any relaxation of the validation procedure described in
Section 6 may allow unwanted Flow Specifications to be propagated and Section 6 may allow unwanted Flow Specifications to be propagated,
thus unwanted Traffic Filtering Actions may be applied to flows. and thus unwanted Traffic Filtering Actions may be applied to flows.
Where the above mechanisms are not in place, this could open the door Where the above mechanisms are not in place, this could open the door
to further denial-of-service attacks such as unwanted traffic to further denial-of-service attacks, such as unwanted traffic
filtering, remarking or redirection. filtering, remarking, or redirection.
Deployment of specific relaxations of the validation within an Deployment of specific relaxations of the validation within an
administrative boundary of a network are useful in some networks for administrative boundary of a network are useful in some networks for
quickly distributing filters to prevent denial-of-service attacks. quickly distributing filters to prevent denial-of-service attacks.
For a network to utilize this relaxation, the BGP policies must For a network to utilize this relaxation, the BGP policies must
support additional filtering since the origin AS field is empty. support additional filtering since the origin AS field is empty.
Specifications relaxing the validation restrictions MUST contain Specifications relaxing the validation restrictions MUST contain
security considerations that provide details on the required security considerations that provide details on the required
additional filtering. For example, the use of Origin validation can additional filtering. For example, the use of origin validation can
provide enhanced filtering within an AS confederation. provide enhanced filtering within an AS confederation.
Inter-provider routing is based on a web of trust. Neighboring Inter-provider routing is based on a web of trust. Neighboring
autonomous systems are trusted to advertise valid reachability autonomous systems are trusted to advertise valid reachability
information. If this trust model is violated, a neighboring information. If this trust model is violated, a neighboring
autonomous system may cause a denial-of-service attack by advertising autonomous system may cause a denial-of-service attack by advertising
reachability information for a given prefix for which it does not reachability information for a given prefix for which it does not
provide service (unfiltered address space hijack). Since validation provide service (unfiltered address space hijack). Since validation
of the Flow Specification is tied to the announcement of the best of the Flow Specification is tied to the announcement of the best
unicast route, the failure in the validation of best path route may unicast route, the failure in the validation of best path route may
prevent the Flow Specificaiton from being used by a local router. prevent the Flow Specification from being used by a local router.
Possible mitigations are [RFC6811] and [RFC8205]. Possible mitigations are [RFC6811] and [RFC8205].
On IXPs routes are often exchanged via route servers which do not On Internet Exchange Points (IXPs), routes are often exchanged via
extend the AS_PATH. In such cases it is not possible to enforce the route servers that do not extend the AS_PATH. In such cases, it is
left-most AS in the AS_PATH to be the neighbor AS (the AS of the not possible to enforce the left-most AS in the AS_PATH to be the
route server). Since the validation of Flow Specification neighbor AS (the AS of the route server). Since the validation of
(Section 6) depends on this, additional care must be taken. It is Flow Specification (Section 6) depends on this, additional care must
advised to use a strict inbound route policy in such scenarios. be taken. It is advised to use a strict inbound route policy in such
scenarios.
Enabling firewall-like capabilities in routers without centralized Enabling firewall-like capabilities in routers without centralized
management could make certain failures harder to diagnose. For management could make certain failures harder to diagnose. For
example, it is possible to allow TCP packets to pass between a pair example, it is possible to allow TCP packets to pass between a pair
of addresses but not ICMP packets. It is also possible to permit of addresses but not ICMP packets. It is also possible to permit
packets smaller than 900 or greater than 1000 octets to pass between packets smaller than 900 or greater than 1000 octets to pass between
a pair of addresses, but not packets whose length is in the range a pair of addresses but not packets whose length is in the range
900- 1000. Such behavior may be confusing and these capabilities 900-1000. Such behavior may be confusing, and these capabilities
should be used with care whether manually configured or coordinated should be used with care whether manually configured or coordinated
through the protocol extensions described in this document. through the protocol extensions described in this document.
Flow Specification BGP speakers (e.g. automated DDoS controllers) not Flow Specification BGP speakers (e.g., automated DDoS controllers)
properly programmed, algorithms that are not performing as expected, not properly programmed, algorithms that are not performing as
or simply rogue systems may announce unintended Flow Specifications, expected, or simply rogue systems may announce unintended Flow
send updates at a high rate or generate a high number of Flow Specifications, send updates at a high rate, or generate a high
Specifications. This may stress the receiving systems, exceed their number of Flow Specifications. This may stress the receiving
capacity, or lead to unwanted Traffic Filtering Actions being applied systems, exceed their capacity, or lead to unwanted Traffic Filtering
to flows. Actions being applied to flows.
Systems may not be able to locate all header values required to
identify a packet. This can be especially problematic in the case of
fragmented packets that are not the first fragment and thus lack
upper-layer protocol headers or Encapsulating Security Payload (ESP)
NULL [RFC4303] encryption.
While the general verification of the Flow Specification NLRI is While the general verification of the Flow Specification NLRI is
specified in this document (Section 6) the Traffic Filtering Actions specified in this document (Section 6), the Traffic Filtering Actions
received by a third party may need custom verification or filtering. received by a third party may need custom verification or filtering.
In particular all non traffic-rate actions may allow a third party to In particular, all non-traffic-rate actions may allow a third party
modify packet forwarding properties and potentially gain access to to modify packet forwarding properties and potentially gain access to
other routing-tables/VPNs or undesired queues. This can be avoided other routing-tables/VPNs or undesired queues. This can be avoided
by proper filtering/screening of the Traffic Filtering Action by proper filtering/screening of the Traffic Filtering Action
communities at network borders and only exposing a predefined subset communities at network borders and only exposing a predefined subset
of Traffic Filtering Actions (see Section 7) to third parties. One of Traffic Filtering Actions (see Section 7) to third parties. One
way to achieve this is by mapping user-defined communities, that can way to achieve this is by mapping user-defined communities, which can
be set by the third party, to Traffic Filtering Actions and not be set by the third party, to Traffic Filtering Actions and not
accepting Traffic Filtering Action extended communities from third accepting Traffic Filtering Action extended communities from third
parties. parties.
This extension adds additional information to Internet routers. This extension adds additional information to Internet routers.
These are limited in terms of the maximum number of data elements These are limited in terms of the maximum number of data elements
they can hold as well as the number of events they are able to they can hold as well as the number of events they are able to
process in a given unit of time. Service providers need to consider process in a given unit of time. Service providers need to consider
the maximum capacity of their devices and may need to limit the the maximum capacity of their devices and may need to limit the
number of Flow Specifications accepted and processed. number of Flow Specifications accepted and processed.
13. Contributors 13. References
Barry Greene, Pedro Marques, Jared Mauch and Nischal Sheth were
authors on [RFC5575], and therefore are contributing authors on this
document.
14. Acknowledgements
The authors would like to thank Yakov Rekhter, Dennis Ferguson, Chris
Morrow, Charlie Kaufman, and David Smith for their comments for the
comments on the original [RFC5575]. Chaitanya Kodeboyina helped
design the flow validation procedure; and Steven Lin and Jim Washburn
ironed out all the details necessary to produce a working
implementation in the original [RFC5575].
A packet rate Traffic Filtering Action was also described in a Flow
Specification extension draft and the authors like to thank Wesley
Eddy, Justin Dailey and Gilbert Clark for their work.
Additionally, the authors would like to thank Alexander Mayrhofer,
Nicolas Fevrier, Job Snijders, Jeffrey Haas and Adam Chappell for
their comments and review.
15. References
15.1. Normative References 13.1. Normative References
[IEEE.754.1985] [IEEE.754.1985]
IEEE, "Standard for Binary Floating-Point Arithmetic", IEEE, "Standard for Binary Floating-Point Arithmetic",
IEEE 754-1985, August 1985. IEEE 754-1985, DOI 10.1109/IEEESTD.2019.8766229, August
1985, <https://doi.org/10.1109/IEEESTD.2019.8766229>.
[ISO_IEC_9899] [ISO_IEC_9899]
ISO, "Information technology -- Programming languages -- ISO, "Information technology -- Programming languages --
C", ISO/IEC 9899:2018, June 2018. C", ISO/IEC 9899:2018, June 2018.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
DOI 10.17487/RFC0768, August 1980, DOI 10.17487/RFC0768, August 1980,
<https://www.rfc-editor.org/info/rfc768>. <https://www.rfc-editor.org/info/rfc768>.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
skipping to change at page 34, line 28 skipping to change at line 1647
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
15.2. Informative References 13.2. Informative References
[I-D.ietf-idr-flow-spec-v6]
Loibl, C., Raszuk, R., and S. Hares, "Dissemination of
Flow Specification Rules for IPv6", draft-ietf-idr-flow-
spec-v6-15 (work in progress), September 2020.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005, RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>. <https://www.rfc-editor.org/info/rfc4303>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J., [RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009, Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<https://www.rfc-editor.org/info/rfc5575>. <https://www.rfc-editor.org/info/rfc5575>.
skipping to change at page 35, line 18 skipping to change at line 1680
[RFC8205] Lepinski, M., Ed. and K. Sriram, Ed., "BGPsec Protocol [RFC8205] Lepinski, M., Ed. and K. Sriram, Ed., "BGPsec Protocol
Specification", RFC 8205, DOI 10.17487/RFC8205, September Specification", RFC 8205, DOI 10.17487/RFC8205, September
2017, <https://www.rfc-editor.org/info/rfc8205>. 2017, <https://www.rfc-editor.org/info/rfc8205>.
[RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger,
"Common YANG Data Types for the Routing Area", RFC 8294, "Common YANG Data Types for the Routing Area", RFC 8294,
DOI 10.17487/RFC8294, December 2017, DOI 10.17487/RFC8294, December 2017,
<https://www.rfc-editor.org/info/rfc8294>. <https://www.rfc-editor.org/info/rfc8294>.
15.3. URIs [RFC8956] Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed.,
"Dissemination of Flow Specification Rules for IPv6",
[1] https://github.com/stoffi92/rfc5575bis/tree/master/flowspec-cmp RFC 8956, DOI 10.17487/RFC8956, December 2020,
<https://www.rfc-editor.org/info/rfc8956>.
[2] https://www.iana.org/assignments/iana-routing-types
Appendix A. Example Python code: flow_rule_cmp Appendix A. Example Python code: flow_rule_cmp
<CODE BEGINS> <CODE BEGINS>
""" """
Copyright (c) 2020 IETF Trust and the persons identified as authors Copyright (c) 2020 IETF Trust and the persons identified as
of draft-ietf-idr-rfc5575bis. All rights reserved. authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without Redistribution and use in source and binary forms, with or without
modification, is permitted pursuant to, and subject to the license modification, is permitted pursuant to, and subject to the license
terms contained in, the Simplified BSD License set forth in Section terms contained in, the Simplified BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info). (https://trustee.ietf.org/license-info).
""" """
import itertools import itertools
import collections import collections
import ipaddress import ipaddress
EQUAL = 0 EQUAL = 0
A_HAS_PRECEDENCE = 1 A_HAS_PRECEDENCE = 1
B_HAS_PRECEDENCE = 2 B_HAS_PRECEDENCE = 2
IP_DESTINATION = 1 IP_DESTINATION = 1
IP_SOURCE = 2 IP_SOURCE = 2
FS_component = collections.namedtuple('FS_component', FS_component = collections.namedtuple('FS_component',
'component_type op_value') 'component_type op_value')
class FS_nlri(object): class FS_nlri(object):
""" """
FS_nlri class implementation that allows sorting. FS_nlri class implementation that allows sorting.
By calling .sort() on a array of FS_nlri objects these will be By calling .sort() on an array of FS_nlri objects these will be
sorted according to the flow_rule_cmp algorithm. sorted according to the flow_rule_cmp algorithm.
Example: Example:
nlri = [ FS_nlri(components=[ nlri = [ FS_nlri(components=[
FS_component(component_type=IP_DESTINATION, FS_component(component_type=IP_DESTINATION,
op_value=ipaddress.ip_network('10.1.0.0/16') ), op_value=ipaddress.ip_network('10.1.0.0/16') ),
FS_component(component_type=4, FS_component(component_type=4,
op_value=bytearray([0,1,2,3,4,5,6])), op_value=bytearray([0,1,2,3,4,5,6])),
]), ]),
FS_nlri(components=[ FS_nlri(components=[
FS_component(component_type=5, FS_component(component_type=5,
op_value=bytearray([0,1,2,3,4,5,6])), op_value=bytearray([0,1,2,3,4,5,6])),
FS_component(component_type=6, FS_component(component_type=6,
op_value=bytearray([0,1,2,3,4,5,6])), op_value=bytearray([0,1,2,3,4,5,6])),
]), ]),
] ]
nlri.sort() # sorts the array accorinding to the algorithm nlri.sort() # sorts the array according to the algorithm
""" """
def __init__(self, components = None): def __init__(self, components = None):
""" """
components: list of type FS_component components: list of type FS_component
""" """
self.components = components self.components = components
def __lt__(self, other): def __lt__(self, other):
# use the below algorithm for sorting # use the below algorithm for sorting
result = flow_rule_cmp(self, other) result = flow_rule_cmp(self, other)
if result == B_HAS_PRECEDENCE: if result == B_HAS_PRECEDENCE:
return True return True
else: else:
return False return False
def flow_rule_cmp(a, b): def flow_rule_cmp(a, b):
""" """
Example of the flowspec comparison algorithm. Example of the flowspec comparison algorithm.
""" """
for comp_a, comp_b in itertools.zip_longest(a.components, for comp_a, comp_b in itertools.zip_longest(a.components,
b.components): b.components):
# If a component type does not exist in one rule # If a component type does not exist in one rule
# this rule has lower precedence # this rule has lower precedence
if not comp_a: if not comp_a:
return B_HAS_PRECEDENCE return B_HAS_PRECEDENCE
if not comp_b:
return A_HAS_PRECEDENCE
# Higher precedence for lower component type
if comp_a.component_type < comp_b.component_type:
return A_HAS_PRECEDENCE
if comp_a.component_type > comp_b.component_type:
return B_HAS_PRECEDENCE
# component types are equal -> type specific comparison
if comp_a.component_type in (IP_DESTINATION, IP_SOURCE):
# assuming comp_a.op_value, comp_b.op_value of
# type ipaddress.IPv4Network
if comp_a.op_value.overlaps(comp_b.op_value):
# longest prefixlen has precedence
if comp_a.op_value.prefixlen > \
comp_b.op_value.prefixlen:
return A_HAS_PRECEDENCE
if comp_a.op_value.prefixlen < \
comp_b.op_value.prefixlen:
return B_HAS_PRECEDENCE
# components equal -> continue with next component
elif comp_a.op_value > comp_b.op_value:
return B_HAS_PRECEDENCE
elif comp_a.op_value < comp_b.op_value:
return A_HAS_PRECEDENCE
else:
# assuming comp_a.op_value, comp_b.op_value of type
# bytearray
if len(comp_a.op_value) == len(comp_b.op_value):
if comp_a.op_value > comp_b.op_value:
return B_HAS_PRECEDENCE
if comp_a.op_value < comp_b.op_value:
return A_HAS_PRECEDENCE
# components equal -> continue with next component
else:
common = min(len(comp_a.op_value),
len(comp_b.op_value))
if comp_a.op_value[:common] > \
comp_b.op_value[:common]:
return B_HAS_PRECEDENCE
elif comp_a.op_value[:common] < \
comp_b.op_value[:common]:
return A_HAS_PRECEDENCE
# the first common bytes match
elif len(comp_a.op_value) > len(comp_b.op_value):
return A_HAS_PRECEDENCE
else:
return B_HAS_PRECEDENCE
return EQUAL
<CODE ENDS>
if not comp_b:
return A_HAS_PRECEDENCE
# Higher precedence for lower component type
if comp_a.component_type < comp_b.component_type:
return A_HAS_PRECEDENCE
if comp_a.component_type > comp_b.component_type:
return B_HAS_PRECEDENCE
# component types are equal -> type specific comparison
if comp_a.component_type in (IP_DESTINATION, IP_SOURCE):
# assuming comp_a.op_value, comp_b.op_value of
# type ipaddress.IPv4Network
if comp_a.op_value.overlaps(comp_b.op_value):
# longest prefixlen has precedence
if comp_a.op_value.prefixlen > \
comp_b.op_value.prefixlen:
return A_HAS_PRECEDENCE
if comp_a.op_value.prefixlen < \
comp_b.op_value.prefixlen:
return B_HAS_PRECEDENCE
# components equal -> continue with next component
elif comp_a.op_value > comp_b.op_value:
return B_HAS_PRECEDENCE
elif comp_a.op_value < comp_b.op_value:
return A_HAS_PRECEDENCE
else:
# assuming comp_a.op_value, comp_b.op_value of type
# bytearray
if len(comp_a.op_value) == len(comp_b.op_value):
if comp_a.op_value > comp_b.op_value:
return B_HAS_PRECEDENCE
if comp_a.op_value < comp_b.op_value:
return A_HAS_PRECEDENCE
# components equal -> continue with next component
else:
common = min(len(comp_a.op_value), len(comp_b.op_value))
if comp_a.op_value[:common] > comp_b.op_value[:common]:
return B_HAS_PRECEDENCE
elif comp_a.op_value[:common] < \
comp_b.op_value[:common]:
return A_HAS_PRECEDENCE
# the first common bytes match
elif len(comp_a.op_value) > len(comp_b.op_value):
return A_HAS_PRECEDENCE
else:
return B_HAS_PRECEDENCE
return EQUAL
<CODE ENDS>
Appendix B. Comparison with RFC 5575 Appendix B. Comparison with RFC 5575
This document includes numerous editorial changes to [RFC5575]. It This document includes numerous editorial changes to [RFC5575]. It
also completely incorporates the redirect action clarification also completely incorporates the redirect action clarification
document [RFC7674]. It is recommended to read the entire document. document [RFC7674]. It is recommended to read the entire document.
The authors, however want to point out the following technical The authors, however, want to point out the following technical
changes to [RFC5575]: changes to [RFC5575]:
Section 1 introduces the Flow Specification NLRI. In [RFC5575] * Section 1 introduces the Flow Specification NLRI. In [RFC5575],
this NLRI was defined as an opaque-key in BGPs database. This BGP treats this NLRI as an opaque key to an entry in its
specification has removed all references to an opaque-key databases. This specification has removed all references to an
property. BGP implementations are able to understand the NLRI opaque key property. BGP implementations are able to understand
encoding. the NLRI encoding.
Section 4.2.1.1 defines a numeric operator and comparison bit * Section 4.2.1.1 defines a numeric operator and comparison bit
combinations. In [RFC5575] the meaning of those bit combination combinations. In [RFC5575], the meaning of those bit combination
was not explicitly defined and left open to the reader. was not explicitly defined and left open to the reader.
Section 4.2.2.3 - Section 4.2.2.8, Section 4.2.2.10, * Sections 4.2.2.3 - 4.2.2.8, 4.2.2.10, and 4.2.2.11 make use of the
Section 4.2.2.11 make use of the above numeric operator. The above numeric operator. The allowed length of the comparison
allowed length of the comparison value was not consistently value was not consistently defined in [RFC5575].
defined in [RFC5575].
Section 7 defines all Traffic Filtering Action Extended * Section 7 defines all Traffic Filtering Action Extended
communities as transitive extended communities. [RFC5575] defined Communities as transitive Extended Communities. [RFC5575] defined
the traffic-rate action to be non-transitive and did not define the traffic-rate action to be non-transitive and did not define
the transitivity of the other Traffic Filtering Action communities the transitivity of the other Traffic Filtering Action communities
at all. at all.
Section 7.2 introduces a new Traffic Filtering Action (traffic- * Section 7.2 introduces a new Traffic Filtering Action (traffic-
rate-packets). This action did not exist in [RFC5575]. rate-packets). This action did not exist in [RFC5575].
Section 7.4 contains the same redirect actions already defined in * Section 7.4 contains the same redirect actions already defined in
[RFC5575] however, these actions have been renamed to "rt- [RFC5575], however, these actions have been renamed to "rt-
redirect" to make it clearer that the redirection is based on redirect" to make it clearer that the redirection is based on
route-target. This section also completely incorporates the route-target. This section also completely incorporates the
[RFC7674] clarifications of the Flowspec Redirect Extended [RFC7674] clarifications of the Flowspec Redirect Extended
Community. Community.
Section 7.7 contains general considerations on interfering traffic * Section 7.7 contains general considerations on interfering traffic
actions. Section 7.3 also cross-references Section 7.7. actions. Section 7.3 also cross-references Section 7.7.
[RFC5575] did not mention this. [RFC5575] did not mention this.
Section 10 contains new error handling. * Section 10 contains new error handling.
Acknowledgments
The authors would like to thank Yakov Rekhter, Dennis Ferguson, Chris
Morrow, Charlie Kaufman, and David Smith for their comments on the
original [RFC5575]. Chaitanya Kodeboyina helped design the flow
validation procedure, and Steven Lin and Jim Washburn ironed out all
the details necessary to produce a working implementation in the
original [RFC5575].
A packet rate Traffic Filtering Action was also described in a Flow
Specification extension draft and the authors would like to thank
Wesley Eddy, Justin Dailey, and Gilbert Clark for their work.
Additionally, the authors would like to thank Alexander Mayrhofer,
Nicolas Fevrier, Job Snijders, Jeffrey Haas, and Adam Chappell for
their comments and review.
Contributors
Barry Greene, Pedro Marques, Jared Mauch, and Nischal Sheth were
authors on [RFC5575] and, therefore, are contributing authors on this
document.
Authors' Addresses Authors' Addresses
Christoph Loibl Christoph Loibl
next layer Telekom GmbH next layer Telekom GmbH
Mariahilfer Guertel 37/7 Mariahilfer Guertel 37/7
Vienna 1150 1150 Vienna
AT Austria
Phone: +43 664 1176414 Phone: +43 664 1176414
Email: cl@tix.at Email: cl@tix.at
Susan Hares Susan Hares
Huawei Huawei
7453 Hickory Hill 7453 Hickory Hill
Saline, MI 48176 Saline, MI 48176
USA United States of America
Email: shares@ndzh.com Email: shares@ndzh.com
Robert Raszuk Robert Raszuk
Bloomberg LP NTT Network Innovations
731 Lexington Ave 940 Stewart Dr
New York City, NY 10022 Sunnyvale, CA 94085
USA United States of America
Email: robert@raszuk.net Email: robert@raszuk.net
Danny McPherson Danny McPherson
Verisign Verisign
USA United States of America
Email: dmcpherson@verisign.com Email: dmcpherson@verisign.com
Martin Bacher Martin Bacher
T-Mobile Austria T-Mobile Austria
Rennweg 97-99 Rennweg 97-99
Vienna 1030 1030 Vienna
AT Austria
Email: mb.ietf@gmail.com Email: mb.ietf@gmail.com
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