draft-ietf-6man-spring-srv6-oam-11.txt   draft-ietf-6man-spring-srv6-oam-12.txt 
6man Z. Ali 6man Z. Ali
Internet-Draft C. Filsfils Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems Intended status: Standards Track Cisco Systems
Expires: December 4, 2021 S. Matsushima Expires: June 1, 2022 S. Matsushima
Softbank Softbank
D. Voyer D. Voyer
Bell Canada Bell Canada
M. Chen M. Chen
Huawei Huawei
June 2, 2021 November 28, 2021
Operations, Administration, and Maintenance (OAM) in Segment Routing Operations, Administration, and Maintenance (OAM) in Segment Routing
Networks with IPv6 Data plane (SRv6) Networks with IPv6 Data plane (SRv6)
draft-ietf-6man-spring-srv6-oam-11 draft-ietf-6man-spring-srv6-oam-12
Abstract Abstract
This document describes how the existing IPv6 mechanisms for ping and This document describes how the existing IPv6 mechanisms for ping and
traceroute can be used in an SRv6 network. The document also traceroute can be used in an SRv6 network. The document also
specifies the OAM flag in the Segment Routing Header (SRH) for specifies the OAM flag in the Segment Routing Header (SRH) for
performing controllable and predictable flow sampling from segment performing controllable and predictable flow sampling from segment
endpoints. In addition, the document describes how a centralized endpoints. In addition, the document describes how a centralized
monitoring system performs a path continuity check between any nodes monitoring system performs a path continuity check between any nodes
within an SRv6 domain. within an SRv6 domain.
skipping to change at page 1, line 43 skipping to change at page 1, line 43
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 4, 2021. This Internet-Draft will expire on June 1, 2022.
Copyright Notice Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the Copyright (c) 2021 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
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 24 skipping to change at page 2, line 24
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3
1.3. Terminology and Reference Topology . . . . . . . . . . . 4 1.3. Terminology and Reference Topology . . . . . . . . . . . 4
2. OAM Mechanisms . . . . . . . . . . . . . . . . . . . . . . . 5 2. OAM Mechanisms . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. O-flag in Segment Routing Header . . . . . . . . . . . . 5 2.1. O-flag in Segment Routing Header . . . . . . . . . . . . 5
2.1.1. O-flag Processing . . . . . . . . . . . . . . . . . . 6 2.1.1. O-flag Processing . . . . . . . . . . . . . . . . . . 6
2.2. OAM Operations . . . . . . . . . . . . . . . . . . . . . 7 2.2. OAM Operations . . . . . . . . . . . . . . . . . . . . . 8
3. Illustrations . . . . . . . . . . . . . . . . . . . . . . . . 8 3. Illustrations . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1. Ping in SRv6 Networks . . . . . . . . . . . . . . . . . . 8 3.1. Ping in SRv6 Networks . . . . . . . . . . . . . . . . . . 9
3.1.1. Classic Ping . . . . . . . . . . . . . . . . . . . . 8 3.1.1. Pinging an IPv6 Address via a Segment-list . . . . . 9
3.1.2. Pinging a SID . . . . . . . . . . . . . . . . . . . . 10 3.1.2. Pinging a SID . . . . . . . . . . . . . . . . . . . . 10
3.2. Traceroute . . . . . . . . . . . . . . . . . . . . . . . 11 3.2. Traceroute . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.1. Classic Traceroute . . . . . . . . . . . . . . . . . 11 3.2.1. Traceroute to an IPv6 Address via a Segment-list . . 11
3.2.2. Traceroute to a SID . . . . . . . . . . . . . . . . . 13 3.2.2. Traceroute to a SID . . . . . . . . . . . . . . . . . 13
3.3. A Hybrid OAM Using O-flag . . . . . . . . . . . . . . . . 15 3.3. A Hybrid OAM Using O-flag . . . . . . . . . . . . . . . . 15
3.4. Monitoring of SRv6 Paths . . . . . . . . . . . . . . . . 17 3.4. Monitoring of SRv6 Paths . . . . . . . . . . . . . . . . 17
4. Implementation Status . . . . . . . . . . . . . . . . . . . . 18 4. Implementation Status . . . . . . . . . . . . . . . . . . . . 18
5. Security Considerations . . . . . . . . . . . . . . . . . . . 18 5. Security Considerations . . . . . . . . . . . . . . . . . . . 18
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 19
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 19 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 20
9.1. Normative References . . . . . . . . . . . . . . . . . . 21 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.2. Informative References . . . . . . . . . . . . . . . . . 21 10.1. Normative References . . . . . . . . . . . . . . . . . . 21
10.2. Informative References . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
As Segment Routing with IPv6 data plane (SRv6) [RFC8402] simply adds As Segment Routing with IPv6 data plane (SRv6) [RFC8402] simply adds
a new type of Routing Extension Header, existing IPv6 OAM mechanisms a new type of Routing Extension Header, existing IPv6 OAM mechanisms
can be used in an SRv6 network. This document describes how the can be used in an SRv6 network. This document describes how the
existing IPv6 mechanisms for ping and traceroute can be used in an existing IPv6 mechanisms for ping and traceroute can be used in an
SRv6 network. This includes illustrations of pinging an SRv6 SID to SRv6 network. This includes illustrations of pinging an SRv6 SID to
verify that the SID is reachable and is locally programmed at the verify that the SID is reachable and is locally programmed at the
target node. This also includes illustrations for tracerouting to an target node. This also includes illustrations for tracerouting to an
SRv6 SID for hop-by-hop fault localization as well as path tracing to SRv6 SID for hop-by-hop fault localization as well as path tracing to
a SID. a SID.
The document also introduces enhancements for OAM mechanism for SRv6 The document also introduces enhancements for the OAM mechanism for
networks for performing controllable and predictable flow sampling SRv6 networks for performing controllable and predictable flow
from segment endpoints using, e.g., IP Flow Information Export sampling from segment endpoints using, e.g., IP Flow Information
(IPFIX) protocol [RFC7011]. Specifically, the document specifies the Export (IPFIX) protocol [RFC7011]. Specifically, the document
O-flag in SRH as a marking-bit in the user packets to trigger the specifies the O-flag in SRH as a marking-bit in the user packets to
telemetry data collection and export at the segment endpoints. trigger the telemetry data collection and export at the segment
endpoints.
The document also outlines how centralized OAM technique in [RFC8403] The document also outlines how the centralized OAM technique in
can be extended for SRv6 to perform a path continuity check between [RFC8403] can be extended for SRv6 to perform a path continuity check
any nodes within an SRv6 domain. Specifically, the document between any nodes within an SRv6 domain. Specifically, the document
illustrates how a centralized monitoring system can monitor arbitrary illustrates how a centralized monitoring system can monitor arbitrary
SRv6 paths by creating the loopback probes that originates and SRv6 paths by creating the loopback probes that originate and
terminates at the centralized monitoring system. terminate at the centralized monitoring system.
1.1. Requirements Language 1.1. Requirements Language
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 BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
1.2. Abbreviations 1.2. Abbreviations
skipping to change at page 3, line 43 skipping to change at page 3, line 45
SID: Segment ID. SID: Segment ID.
SL: Segments Left. SL: Segments Left.
SR: Segment Routing. SR: Segment Routing.
SRH: Segment Routing Header [RFC8754]. SRH: Segment Routing Header [RFC8754].
SRv6: Segment Routing with IPv6 Data plane. SRv6: Segment Routing with IPv6 Data plane.
TC: Traffic Class. PSP: Penultimate Segment Pop of the SRH [RFC8986].
USP: Ultimate Segment Pop of the SRH [RFC8986].
ICMPv6: ICMPv6 Specification [RFC4443]. ICMPv6: ICMPv6 Specification [RFC4443].
IS-IS: Intermediate System to Intermediate System IS-IS: Intermediate System to Intermediate System
OSPF: Open Shortest Path First protocol [RFC2328] OSPF: Open Shortest Path First protocol [RFC2328]
IGP: Interior Gateway Protocols (e.g., OSPF, IS-IS). IGP: Interior Gateway Protocols (e.g., OSPF, IS-IS).
BGP-LS: Border Gateway Protocol - Link State Extensions [RFC8571] BGP-LS: Border Gateway Protocol - Link State Extensions [RFC8571]
1.3. Terminology and Reference Topology 1.3. Terminology and Reference Topology
Throughout the document, the following terminology and simple Throughout the document, the following terminology and simple
topology is used for illustration. topology is used for illustration.
skipping to change at page 4, line 28 skipping to change at page 4, line 31
| | | | | | | |
---+-- | ------ | --+--- ---+-- | ------ | --+---
|CE 1| +-------| N6 |---------+ |CE 2| |CE 1| +-------| N6 |---------+ |CE 2|
------ link7 | | link8 ------ ------ link7 | | link8 ------
------ ------
Figure 1 Reference Topology Figure 1 Reference Topology
In the reference topology: In the reference topology:
Node k has a IPv6 loopback address 2001:db8::A:k::/128. Node j has a IPv6 loopback address 2001:db8:L:j::/128.
Nodes N1, N2, N4 and N7 are SRv6-capable nodes. Nodes N1, N2, N4 and N7 are SRv6-capable nodes.
Nodes N3, N5 and N6 are IPv6 nodes that are not SRv6-capable. Nodes N3, N5 and N6 are IPv6 nodes that are not SRv6-capable.
Such nodes are referred as classic IPv6 nodes. Such nodes are referred as non-SRv6 capable nodes.
CE1 and CE2 are Customer Edge devices of any data plane capability CE1 and CE2 are Customer Edge devices of any data plane capability
(e.g., IPv4, IPv6, L2, etc.). (e.g., IPv4, IPv6, L2, etc.).
A SID at node k with locator block 2001:db8:B::/48 and function F A SID at node j with locator block 2001:db8:K::/48 and function U
is represented by 2001:db8:B:k:F::. is represented by 2001:db8:K:j:U::.
Node N100 is a controller. Node N100 is a controller.
The IPv6 address of the nth Link between node i and j at the i The IPv6 address of the nth Link between node i and j at the i
side is represented as 2001:db8:i:j:in::, e.g., the IPv6 address side is represented as 2001:db8:i:j:in::, e.g., the IPv6 address
of link6 (the 2nd link) between N3 and N4 at N3 in Figure 1 is of link6 (the 2nd link between N3 and N4) at N3 in Figure 1 is
2001:db8:3:4:32::. Similarly, the IPv6 address of link5 (the 1st 2001:db8:3:4:32::. Similarly, the IPv6 address of link5 (the 1st
link between N3 and N4) at node 3 is 2001:db8:3:4:31::. link between N3 and N4) at node N3 is 2001:db8:3:4:31::.
2001:db8:B:k:Cij:: is explicitly allocated as the END.X SID at 2001:db8:K:j:Xin:: is explicitly allocated as the End.X SID at
node k towards neighbor node i via jth Link between node i and node j towards neighbor node i via nth Link between node i and
node k. e.g., 2001:db8:B:2:C31:: represents END.X at N2 towards node j. e.g., 2001:db8:K:2:X31:: represents End.X at N2 towards
N3 via link3 (the 1st link between N2 and N3). Similarly, N3 via link3 (the 1st link between N2 and N3). Similarly,
2001:db8:B:4:C52:: represents the END.X at N4 towards N5 via 2001:db8:K:4:X52:: represents the End.X at N4 towards N5 via
link10. Please refer to [RFC8986] for description of END.X SID. link10 (the 2nd link between N4 and N5). Please refer to
[RFC8986] for description of End.X SID.
A SID list is represented as <S1, S2, S3> where S1 is the first A SID list is represented as <S1, S2, S3> where S1 is the first
SID to visit, S2 is the second SID to visit and S3 is the last SID SID to visit, S2 is the second SID to visit and S3 is the last SID
to visit along the SR path. to visit along the SR path.
(SA,DA) (S3, S2, S1; SL)(payload) represents an IPv6 packet with: (SA,DA) (S3, S2, S1; SL)(payload) represents an IPv6 packet with:
* IPv6 header with source address SA, destination addresses DA * IPv6 header with source address SA, destination addresses DA
and SRH as next-header and SRH as next-header
skipping to change at page 5, line 50 skipping to change at page 6, line 7
This document defines the following bit in the SRH Flags field to This document defines the following bit in the SRH Flags field to
carry the O-flag: carry the O-flag:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| |O| | | |O| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Where: Where:
O-flag: OAM flag in the SRH Flags field defined in [RFC8754] . O-flag: OAM flag in the SRH Flags field defined in [RFC8754].
2.1.1. O-flag Processing 2.1.1. O-flag Processing
The O-flag in SRH is used as a marking-bit in the user packets to The O-flag in SRH is used as a marking-bit in the user packets to
trigger the telemetry data collection and export at the segment trigger the telemetry data collection and export at the segment
endpoints. endpoints.
An SR domain ingress edge node encapsulates packets traversing the SR
domain as defined in [RFC8754]. The SR domain ingress edge node MAY
use the O-flag in SRH for marking the packet to trigger the telemetry
data collection and export at the segment endpoints. Based on a
local configuration, the SR domain ingress edge node may implement a
classification and sampling mechanism to mark a packet with the
O-flag in SRH. Specification of the classification and sampling
method is outside the scope of this document.
This document does not specify the data elements that need to be This document does not specify the data elements that need to be
exported and the associated configurations. Similarly, this document exported and the associated configurations. Similarly, this document
does not define any formats for exporting the data elements. does not define any formats for exporting the data elements.
Nonetheless, without the loss of generality, this document assumes IP Nonetheless, without the loss of generality, this document assumes IP
Flow Information Export (IPFIX) protocol [RFC7011] is used for Flow Information Export (IPFIX) protocol [RFC7011] is used for
exporting the traffic flow information from the network devices to a exporting the traffic flow information from the network devices to a
controller for monitoring and analytics. Similarly, without the loss controller for monitoring and analytics. Similarly, without the loss
of generality, this document assumes requested information elements of generality, this document assumes requested information elements
are configured by the management plane through data set templates are configured by the management plane through data set templates
(e.g., as in IPFIX [RFC7012]). (e.g., as in IPFIX [RFC7012]).
Implementation of the O-flag is OPTIONAL. If a node does not support Implementation of the O-flag is OPTIONAL. If a node does not support
the O-flag, then upon reception it simply ignores it. If a node the O-flag, then upon reception it simply ignores it. If a node
supports the O-flag, it can optionally advertise its potential via supports the O-flag, it can optionally advertise its potential via
control plane protocol(s). control plane protocol(s).
When N receives a packet whose IPv6 DA is S and S is a local SID, the When N receives a packet destined to S and S is a local SID, the line
line S01 of the pseudo-code associated with the SID S, as defined in S01 of the pseudo-code associated with the SID S, as defined in
section 4.3.1.1 of [RFC8754], is appended as follows for the O-flag section 4.3.1.1 of [RFC8754], is appended to as follows for the
processing. O-flag processing.
S01.1. IF O-flag is set and local configuration permits S01.1. IF O-flag is set and local configuration permits
O-flag processing { O-flag processing {
a. Make a copy of the packet. a. Make a copy of the packet.
b. Send the copied packet, along with a timestamp b. Send the copied packet, along with a timestamp
to the OAM process for telemetry data collection to the OAM process for telemetry data collection
and export. ;; Ref1 and export. ;; Ref1
} }
Ref1: An implementation SHOULD copy and record the timestamp as Ref1: To provide an accurate timestamp, an implementation should copy
soon as possible during packet processing. Timestamp or any other and record the timestamp as soon as possible during packet processing.
metadata is not Timestamp and any other metadata is not carried in the packet forwarded to the next hop.
carried in the packet forwarded to the next hop.
Please note that the O-flag processing happens before execution of Please note that the O-flag processing happens before execution of
regular processing of the local SID S. Specifically, the line S01.1 regular processing of the local SID S. Specifically, the line S01.1
of the pseudo-code specified in this document is inserted between of the pseudo-code specified in this document is inserted between
line S01 and S02 of the pseudo-code defined in section 4.3.1.1 of line S01 and S02 of the pseudo-code defined in section 4.3.1.1 of
[RFC8754]. [RFC8754].
Based on the requested information elements configured by the Based on the requested information elements configured by the
management plane through data set templates [RFC7012], the OAM management plane through data set templates [RFC7012], the OAM
process exports the requested information elements. The information process exports the requested information elements. The information
elements include parts of the packet header and/or parts of the elements include parts of the packet header and/or parts of the
packet payload for flow identification. The OAM process uses packet payload for flow identification. The OAM process uses
information elements defined in IPFIX [RFC7011] and PSAMP [RFC5476] information elements defined in IPFIX [RFC7011] and PSAMP [RFC5476]
for exporting the requested sections of the mirrored packets. for exporting the requested sections of the mirrored packets.
If the telemetry data from the ultimate segment in the segment-list If the penultimate segment of a segment-list is a Penultimate Segment
is required, a penultimate segment SHOULD NOT be a Penultimate Pop (PSP) SID, telemetry data from the ultimate segment cannot be
Segment Pop (PSP) SID. When the penultimate segment is a PSP SID, requested. This is because, when the penultimate segment is a PSP
the SRH will be removed and the O-flag will not be processed at the SID, the SRH is removed at the penultimate segment and the O-flag is
ultimate segment. not processed at the ultimate segment.
The processing node SHOULD rate-limit the number of packets punted to The processing node MUST rate-limit the number of packets punted to
the OAM process to a configurable rate. This is to avoid hitting any the OAM process to a configurable rate. This is to avoid hitting any
performance impact on the OAM and the telemetry collection processes. performance impact on the OAM and the telemetry collection processes.
Failure in implementing the rate limit can lead to a denial-of- Failure in implementing the rate limit can lead to a denial-of-
service attack, as detailed in Section 5. service attack, as detailed in Section 5.
The OAM process MUST NOT process the copy of the packet or respond to The OAM process MUST NOT process the copy of the packet or respond to
any upper-layer header (like ICMP, UDP, etc.) payload to prevent any upper-layer header (like ICMP, UDP, etc.) payload to prevent
multiple evaluations of the datagram. multiple evaluations of the datagram.
The OAM process is expected to be located on the routing node The OAM process is expected to be located on the routing node
skipping to change at page 8, line 14 skipping to change at page 8, line 34
message processing [I-D.gandhi-spring-stamp-srpm], etc.). message processing [I-D.gandhi-spring-stamp-srpm], etc.).
Specifically, as long as local configuration allows the Upper-layer Specifically, as long as local configuration allows the Upper-layer
Header processing of the applicable OAM payload for SRv6 SIDs, the Header processing of the applicable OAM payload for SRv6 SIDs, the
existing IPv6 OAM techniques can be used to target a probe to a existing IPv6 OAM techniques can be used to target a probe to a
(remote) SID. (remote) SID.
IPv6 OAM operations can be performed with the target SID in the IPv6 IPv6 OAM operations can be performed with the target SID in the IPv6
destination address without SRH or with SRH where the target SID is destination address without SRH or with SRH where the target SID is
the last segment. In general, OAM operations to a target SID may not the last segment. In general, OAM operations to a target SID may not
exercise all of its processing depending on its behavior definition. exercise all of its processing depending on its behavior definition.
For example, ping to an END.X SID [RFC8986] only validates the SID is For example, ping to an End.X SID [RFC8986] only validates the SID is
locally programmed at the target node and does not validate switching locally programmed at the target node and does not validate switching
to the correct outgoing interface. To exercise the behavior of a to the correct outgoing interface. To exercise the behavior of a
target SID, the OAM operation SHOULD construct the probe in a manner target SID, the OAM operation should construct the probe in a manner
similar to a data packet that exercises the SID behavior, i.e. to similar to a data packet that exercises the SID behavior, i.e. to
include that SID as a transit SID in either an SRH or IPv6 DA of an include that SID as a transit SID in either an SRH or IPv6 DA of an
outer IPv6 header or as appropriate based on the definition of the outer IPv6 header or as appropriate based on the definition of the
SID behavior. SID behavior.
3. Illustrations 3. Illustrations
This section shows how some of the existing IPv6 OAM mechanisms can This section shows how some of the existing IPv6 OAM mechanisms can
be used in an SRv6 network. It also illustrates an OAM mechanism for be used in an SRv6 network. It also illustrates an OAM mechanism for
performing controllable and predictable flow sampling from segment performing controllable and predictable flow sampling from segment
endpoints. How centralized OAM technique in [RFC8403] can be endpoints. How centralized OAM technique in [RFC8403] can be
extended for SRv6 is also described in this Section. extended for SRv6 is also described in this Section.
3.1. Ping in SRv6 Networks 3.1. Ping in SRv6 Networks
The following subsections outline some use cases of the ICMPv6 ping The existing mechanism to perform the reachability checks, along the
in the SRv6 networks. shortest path, continues to work without any modification. Any IPv6
node (SRv6 capable or a non-SRv6 capable) can initiate, transit, and
egress a ping packet.
3.1.1. Classic Ping The following subsections outline some additional use cases of the
ICMPv6 ping in the SRv6 networks.
The existing mechanism to perform the reachability checks, along the 3.1.1. Pinging an IPv6 Address via a Segment-list
shortest path, continues to work without any modification. The
initiator may be an SRv6 node or a classic IPv6 node. Similarly, the
egress or transit may be an SRv6-capable node or a classic IPv6 node.
If an SRv6-capable ingress node wants to ping an IPv6 address via an If an SRv6-capable ingress node wants to ping an IPv6 address via an
arbitrary segment list <S1, S2, S3>, it needs to initiate ICMPv6 ping arbitrary segment list <S1, S2, S3>, it needs to initiate an ICMPv6
with an SR header containing the SID list <S1, S2, S3>. This is ping with an SR header containing the SID list <S1, S2, S3>. This is
illustrated using the topology in Figure 1. Assume all the links illustrated using the topology in Figure 1. User issues a ping from
have IGP metric 10 except both links between N2 and N3, which have node N1 to a loopback of node N5, via segment list
IGP metric set to 100. User issues a ping from node N1 to a loopback <2001:db8:K:2:X31::, 2001:db8:K:4:X52::>. The SID behavior used in
of node 5, via segment list <2001:db8:B:2:C31::, 2001:db8:B:4:C52::>. the example is End.X SID, as described in [RFC8986], but the
The SID behavior used in the example is End.X SID, as described in procedure is equally applicable to any other (transit) SID type.
[RFC8986], but the procedure is equally applicable to any other
(transit) SID type.
Figure 2 contains sample output for a ping request initiated at node Figure 2 contains sample output for a ping request initiated at node
N1 to the loopback address of node N5 via a segment list N1 to a loopback address of node N5 via a segment list
<2001:db8:B:2:C31::, 2001:db8:B:4:C52::>. <2001:db8:K:2:X31::, 2001:db8:K:4:X52::>.
> ping 2001:db8:A:5:: via segment-list 2001:db8:B:2:C31::, > ping 2001:db8:L:5:: via segment-list 2001:db8:K:2:X31::,
2001:db8:B:4:C52:: 2001:db8:K:4:X52::
Sending 5, 100-byte ICMPv6 Echos to B5::, timeout is 2 seconds: Sending 5, 100-byte ICMPv6 Echos to B5::, timeout is 2 seconds:
!!!!! !!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0.625 Success rate is 100 percent (5/5), round-trip min/avg/max = 0.625
/0.749/0.931 ms /0.749/0.931 ms
Figure 2 A sample ping output at an SRv6-capable node Figure 2 A sample ping output at an SRv6-capable node
All transit nodes process the echo request message like any other All transit nodes process the echo request message like any other
data packet carrying SR header and hence do not require any change. data packet carrying SR header and hence do not require any change.
Similarly, the egress node (IPv6 classic or SRv6-capable) does not Similarly, the egress node does not require any change to process the
require any change to process the ICMPv6 echo request. For example, ICMPv6 echo request. For example, in the ping example of Figure 2:
in the ping example of Figure 2:
o Node N1 initiates an ICMPv6 ping packet with SRH as follows o Node N1 initiates an ICMPv6 ping packet with SRH as follows
(2001:db8:A:1::, 2001:db8:B:2:C31::) (2001:db8:A:5::, (2001:db8:L:1::, 2001:db8:K:2:X31::) (2001:db8:L:5::,
2001:db8:B:4:C52::, 2001:db8:B:2:C31::, SL=2, NH = ICMPv6)(ICMPv6 2001:db8:K:4:X52::, 2001:db8:K:2:X31::, SL=2, NH = ICMPv6)(ICMPv6
Echo Request). Echo Request).
o Node N2, which is an SRv6-capable node, performs the standard SRH o Node N2, which is an SRv6-capable node, performs the standard SRH
processing. Specifically, it executes the END.X behavior processing. Specifically, it executes the End.X behavior
(2001:db8:B:2:C31::) and forwards the packet on link3 to N3. indicated by the 2001:db8:K:2:X31:: SID and forwards the packet on
link3 to N3.
o Node N3, which is a classic IPv6 node, performs the standard IPv6 o Node N3, which is a non-SRv6 capable node, performs the standard
processing. Specifically, it forwards the echo request based on IPv6 processing. Specifically, it forwards the echo request based
the DA 2001:db8:B:4:C52:: in the IPv6 header. on the DA 2001:db8:K:4:X52:: in the IPv6 header.
o Node N4, which is an SRv6-capable node, performs the standard SRH o Node N4, which is an SRv6-capable node, performs the standard SRH
processing. Specifically, it observes the END.X behavior processing. Specifically, it observes the End.X behavior
(2001:db8:B:4:C52::) and forwards the packet on link10 towards N5. (2001:db8:K:4:X52::) and forwards the packet on link10 towards N5.
If 2001:db8:B:4:C52:: is a PSP SID, The penultimate node (Node N4) If 2001:db8:K:4:X52:: is a PSP SID, the penultimate node (Node N4)
does not, should not and cannot differentiate between the data does not, should not and cannot differentiate between the data
packets and OAM probes. Specifically, if 2001:db8:B:4:C52:: is a packets and OAM probes. Specifically, if 2001:db8:K:4:X52:: is a
PSP SID, node N4 executes the SID like any other data packet with PSP SID, node N4 executes the SID like any other data packet with
DA = 2001:db8:B:4:C52:: and removes the SRH. DA = 2001:db8:K:4:X52:: and removes the SRH.
o The echo request packet at N5 arrives as an IPv6 packet with or o The echo request packet at N5 arrives as an IPv6 packet with or
without an SRH. If N5 receives the packet with SRH, it skips SRH without an SRH. If N5 receives the packet with SRH, it skips SRH
processing (SL=0). In either case, Node N5 performs the standard processing (SL=0). In either case, Node N5 performs the standard
ICMPv6 processing on the echo request and responds with the echo ICMPv6 processing on the echo request and responds with the echo
reply message to N1. The echo reply message is IP routed. reply message to N1. The echo reply message is IP routed.
3.1.2. Pinging a SID 3.1.2. Pinging a SID
The classic ping described in the previous section applies equally to The ping mechanism described above applies equally to perform SID
perform SID reachability check and to validate the SID is locally reachability check and to validate the SID is locally programmed at
programmed at the target node. This is explained using an example in the target node. This is explained using an example in the
the following. The example uses ping to an END SID, as described in following. The example uses ping to an END SID, as described in
[RFC8986], but the procedure is equally applicable to ping any other [RFC8986], but the procedure is equally applicable to ping any other
SID behaviors. SID behaviors.
Consider the example where the user wants to ping a remote SID Consider the example where the user wants to ping a remote SID
2001:db8:B:4::, via 2001:db8:B:2:C31::, from node N1. The ICMPv6 2001:db8:K:4::, via 2001:db8:K:2:X31::, from node N1. The ICMPv6
echo request is processed at the individual nodes along the path as echo request is processed at the individual nodes along the path as
follows: follows:
o Node N1 initiates an ICMPv6 ping packet with SRH as follows o Node N1 initiates an ICMPv6 ping packet with SRH as follows
(2001:db8:A:1::, 2001:db8:B:2:C31::) (2001:db8:B:4::, (2001:db8:L:1::, 2001:db8:K:2:X31::) (2001:db8:K:4::,
2001:db8:B:2:C31::; SL=1; NH=ICMPv6)(ICMPv6 Echo Request). 2001:db8:K:2:X31::; SL=1; NH=ICMPv6)(ICMPv6 Echo Request).
o Node N2, which is an SRv6-capable node, performs the standard SRH o Node N2, which is an SRv6-capable node, performs the standard SRH
processing. Specifically, it executes the END.X behavior processing. Specifically, it executes the End.X behavior
(2001:db8:B:2:C31::) on the echo request packet. If indicated by the 2001:db8:K:2:X31:: SID on the echo request
2001:db8:B:2:C31:: is a PSP SID, node N4 executes the SID like any packet. If 2001:db8:K:2:X31:: is a PSP SID, node N4 executes the
other data packet with DA = 2001:db8:B:2:C31:: and removes the SID like any other data packet with DA = 2001:db8:K:2:X31:: and
SRH. removes the SRH.
o Node N3, which is a classic IPv6 node, performs the standard IPv6 o Node N3, which is a non-SRv6 capable node, performs the standard
processing. Specifically, it forwards the echo request based on IPv6 processing. Specifically, it forwards the echo request based
DA = 2001:db8:B:4:: in the IPv6 header. on DA = 2001:db8:K:4:: in the IPv6 header.
o When node N4 receives the packet, it processes the target SID o When node N4 receives the packet, it processes the target SID
(2001:db8:B:4::). (2001:db8:K:4::).
o If the target SID (2001:db8:B:4::) is not locally instantiated, o If the target SID (2001:db8:K:4::) is not locally instantiated and
the packet is discarded does not represent a local interface, the packet is discarded
o If the target SID (2001:db8:B:4::) is locally instantiated, the o If the target SID (2001:db8:K:4::) is locally instantiated or
node processes the upper layer header. As part of the upper layer represents a local interface, the node processes the upper layer
header processing node N4 respond to the ICMPv6 echo request header. As part of the upper layer header processing node N4
message and responds with the echo reply message. The echo reply respond to the ICMPv6 echo request message and responds with the
message is IP routed. echo reply message. The echo reply message is IP routed.
3.2. Traceroute 3.2. Traceroute
There is no hardware or software change required for traceroute The existing traceroute mechanisms, along the shortest path,
operation at the classic IPv6 nodes in an SRv6 network. That continues to work without any modification. Any IPv6 node (SRv6
includes the classic IPv6 node with ingress, egress or transit roles. capable or a non-SRv6 capable) can initiate, transit, and egress a
Furthermore, no protocol changes are required to the standard traceroute probe.
traceroute operations. In other words, existing traceroute
mechanisms work seamlessly in the SRv6 networks.
The following subsections outline some use cases of the traceroute in
the SRv6 networks.
3.2.1. Classic Traceroute The following subsections outline some additional use cases of the
traceroute in the SRv6 networks.
The existing mechanism to traceroute a remote IP address, along the 3.2.1. Traceroute to an IPv6 Address via a Segment-list
shortest path, continues to work without any modification. The
initiator may be an SRv6 node or a classic IPv6 node. Similarly, the
egress or transit may be an SRv6 node or a classic IPv6 node.
If an SRv6-capable ingress node wants to traceroute to IPv6 address If an SRv6-capable ingress node wants to traceroute to IPv6 address
via an arbitrary segment list <S1, S2, S3>, it needs to initiate via an arbitrary segment list <S1, S2, S3>, it needs to initiate a
traceroute probe with an SR header containing the SID list <S1, S2, traceroute probe with an SR header containing the SID list <S1, S2,
S3>. That is illustrated using the topology in Figure 1. Assume all S3>. User issues a traceroute from node N1 to a loopback of node N5,
the links have IGP metric 10 except both links between N2 and N3, via segment list <2001:db8:K:2:X31::, 2001:db8:K:4:X52::>. The SID
which have IGP metric set to 100. User issues a traceroute from node behavior used in the example is End.X SID, as described in [RFC8986],
N1 to a loopback of node 5, via segment list <2001:db8:B:2:C31::, but the procedure is equally applicable to any other (transit) SID
2001:db8:B:4:C52::>. The SID behavior used in the example is End.X type. Figure 3 contains sample output for the traceroute request.
SID, as described in [RFC8986], but the procedure is equally
applicable to any other (transit) SID type. Figure 3 contains sample
output for the traceroute request.
> traceroute 2001:db8:A:5:: via segment-list 2001:db8:B:2:C31::, > traceroute 2001:db8:L:5:: via segment-list 2001:db8:K:2:X31::,
2001:db8:B:4:C52:: 2001:db8:K:4:X52::
Tracing the route to 2001:db8:A:5:: Tracing the route to 2001:db8:L:5::
1 2001:db8:1:2:21:: 0.512 msec 0.425 msec 0.374 msec 1 2001:db8:2:1:21:: 0.512 msec 0.425 msec 0.374 msec
DA: 2001:db8:B:2:C31::, DA: 2001:db8:K:2:X31::,
SRH:(2001:db8:A:5::, 2001:db8:B:4:C52::, 2001:db8:B:2:C31::, SL=2) SRH:(2001:db8:L:5::, 2001:db8:K:4:X52::, 2001:db8:K:2:X31::, SL=2)
2 2001:db8:2:3:31:: 0.721 msec 0.810 msec 0.795 msec 2 2001:db8:3:2:31:: 0.721 msec 0.810 msec 0.795 msec
DA: 2001:db8:B:4:C52::, DA: 2001:db8:K:4:X52::,
SRH:(2001:db8:A:5::, 2001:db8:B:4:C52::, 2001:db8:B:2:C31::, SL=1) SRH:(2001:db8:L:5::, 2001:db8:K:4:X52::, 2001:db8:K:2:X31::, SL=1)
3 2001:db8:3:4::41:: 0.921 msec 0.816 msec 0.759 msec 3 2001:db8:4:3::41:: 0.921 msec 0.816 msec 0.759 msec
DA: 2001:db8:B:4:C52::, DA: 2001:db8:K:4:X52::,
SRH:(2001:db8:A:5::, 2001:db8:B:4:C52::, 2001:db8:B:2:C31::, SL=1) SRH:(2001:db8:L:5::, 2001:db8:K:4:X52::, 2001:db8:K:2:X31::, SL=1)
4 2001:db8:4:5::52:: 0.879 msec 0.916 msec 1.024 msec 4 2001:db8:5:4::52:: 0.879 msec 0.916 msec 1.024 msec
DA: 2001:db8:A:5:: DA: 2001:db8:L:5::
Figure 3 A sample traceroute output at an SRv6-capable node Figure 3 A sample traceroute output at an SRv6-capable node
In the sample traceroute output, the information displayed at each In the sample traceroute output, the information displayed at each
hop is obtained using the contents of the "Time Exceeded" or hop is obtained using the contents of the "Time Exceeded" or
"Destination Unreachable" ICMPv6 responses. These ICMPv6 responses "Destination Unreachable" ICMPv6 responses. These ICMPv6 responses
are IP routed. are IP routed.
In the sample traceroute output, the information for link3 is In the sample traceroute output, the information for link3 is
returned by N3, which is a classic IPv6 node. Nonetheless, the returned by N3, which is a non-SRv6 capable node. Nonetheless, the
ingress node is able to display SR header contents as the packet ingress node is able to display SR header contents as the packet
travels through the IPv6 classic node. This is because the "Time travels through the IPv6 classic node. This is because the "Time
Exceeded Message" ICMPv6 message can contain as much of the invoking Exceeded Message" ICMPv6 message can contain as much of the invoking
packet as possible without the ICMPv6 packet exceeding the minimum packet as possible without the ICMPv6 packet exceeding the minimum
IPv6 MTU [RFC4443]. The SR header is also included in these ICMPv6 IPv6 MTU [RFC4443]. The SR header is included in these ICMPv6
messages initiated by the classic IPv6 transit nodes that are not messages initiated by the non-SRv6 capable transit nodes that are not
running SRv6 software. Specifically, a node generating ICMPv6 running SRv6 software. Specifically, a node generating ICMPv6
message containing a copy of the invoking packet does not need to message containing a copy of the invoking packet does not need to
understand the extension header(s) in the invoking packet. understand the extension header(s) in the invoking packet.
The segment list information returned for the first hop is returned The segment list information returned for the first hop is returned
by N2, which is an SRv6-capable node. Just like for the second hop, by N2, which is an SRv6-capable node. Just like for the second hop,
the ingress node is able to display SR header contents for the first the ingress node is able to display SR header contents for the first
hop. hop.
There is no difference in processing of the traceroute probe at an There is no difference in processing of the traceroute probe at an
IPv6 classic node and an SRv6-capable node. Similarly, both IPv6 IPv6 classic node and an SRv6-capable node. Similarly, both IPv6
classic and SRv6-capable nodes may use the address of the interface classic and SRv6-capable nodes may use the address of the interface
on which probe was received as the source address in the ICMPv6 on which probe was received as the source address in the ICMPv6
response. ICMPv6 extensions defined in [RFC5837] can be used to also response. ICMPv6 extensions defined in [RFC5837] can be used to
display information about the IP interface through which the datagram display information about the IP interface through which the datagram
would have been forwarded had it been forwardable, and the IP next would have been forwarded had it been forwardable, and the IP next
hop to which the datagram would have been forwarded, the IP interface hop to which the datagram would have been forwarded, the IP interface
upon which a datagram arrived, the sub-IP component of an IP upon which a datagram arrived, the sub-IP component of an IP
interface upon which a datagram arrived. interface upon which a datagram arrived.
The IP address of the interface on which the traceroute probe was The IP address of the interface on which the traceroute probe was
received is useful. This information can also be used to verify if received is useful. This information can also be used to verify if
SIDs 2001:db8:B:2:C31:: and 2001:db8:B:4:C52:: are executed correctly SIDs 2001:db8:K:2:X31:: and 2001:db8:K:4:X52:: are executed correctly
by N2 and N4, respectively. Specifically, the information displayed by N2 and N4, respectively. Specifically, the information displayed
for the second hop contains the incoming interface address for the second hop contains the incoming interface address
2001:db8:2:3:31:: at N3. This matches with the expected interface 2001:db8:2:3:31:: at N3. This matches with the expected interface
bound to END.X behavior 2001:db8:B:2:C31:: (link3). Similarly, the bound to End.X behavior 2001:db8:K:2:X31:: (link3). Similarly, the
information displayed for hop5 contains the incoming interface information displayed for the fourth hop contains the incoming
address 2001:db8:4:5::52:: at N5. This matches with the expected interface address 2001:db8:4:5::52:: at N5. This matches with the
interface bound to the END.X behavior 2001:db8:B:4:C52:: (link10). expected interface bound to the End.X behavior 2001:db8:K:4:X52::
(link10).
3.2.2. Traceroute to a SID 3.2.2. Traceroute to a SID
The classic traceroute described in the previous section applies The classic traceroute described in the previous section applies
equally to traceroute a remote SID behavior, as explained using an equally to traceroute a remote SID behavior, as explained using an
example in the following. The example uses traceroute to an END SID, example in the following. The example uses traceroute to an END SID,
as described in [RFC8986], but the procedure is equally applicable to as described in [RFC8986], but the procedure is equally applicable to
tracerouting any other SID behaviors. tracerouting any other SID behaviors.
Please note that traceroute to a SID is exemplified using UDP probes. Please note that traceroute to a SID is exemplified using UDP probes.
However, the procedure is equally applicable to other implementations However, the procedure is equally applicable to other implementations
of traceroute mechanism. The UDP encoded message to traceroute a SID of traceroute mechanism. The UDP encoded message to traceroute a SID
uses the UDP ports assigned by IANA for "traceroute use". would use the UDP ports assigned by IANA for "traceroute use".
Consider the example where the user wants to traceroute a remote SID Consider the example where the user wants to traceroute a remote SID
2001:db8:B:4::, via 2001:db8:B:2:C31::, from node N1. The traceroute 2001:db8:K:4::, via 2001:db8:K:2:X31::, from node N1. The traceroute
probe is processed at the individual nodes along the path as follows: probe is processed at the individual nodes along the path as follows:
o Node N1 initiates a traceroute probe packet with a monotonically o Node N1 initiates a traceroute probe packet as follows
increasing value of hop count and SRH as follows (2001:db8:A:1::, (2001:db8:L:1::, 2001:db8:K:2:X31::) (2001:db8:K:4::,
2001:db8:B:2:C31::) (2001:db8:B:4::, 2001:db8:B:2:C31::; SL=1; 2001:db8:K:2:X31::; SL=1; NH=UDP)(Traceroute probe). The first
NH=UDP)(Traceroute probe). traceroute probe is sent with hop-count value set to 1. The hop-
count value is incremented by 1 for each following traceroute
probes.
o When node N2 receives the packet with hop-count = 1, it processes o When node N2 receives the packet with hop-count = 1, it processes
the hop count expiry. Specifically, the node N2 responses with the hop-count expiry. Specifically, the node N2 responds with the
the ICMPv6 message (Type: "Time Exceeded", Code: "Hop limit ICMPv6 message (Type: "Time Exceeded", Code: "Hop limit exceeded
exceeded in transit"). The ICMPv6 response is IP routed. in transit"). The ICMPv6 response is IP routed.
o When Node N2 receives the packet with hop-count > 1, it performs o When Node N2 receives the packet with hop-count > 1, it performs
the standard SRH processing. Specifically, it executes the END.X the standard SRH processing. Specifically, it executes the End.X
behavior (2001:db8:B:2:C31::) on the traceroute probe. If behavior indicated by the 2001:db8:K:2:X31:: SID on the traceroute
2001:db8:B:2:C31:: is a PSP SID, node N4 executes the SID like any probe. If 2001:db8:K:2:X31:: is a PSP SID, node N2 executes the
other data packet with DA = 2001:db8:B:2:C31:: and removes the SID like any other data packet with DA = 2001:db8:K:2:X31:: and
SRH. removes the SRH.
o When node N3, which is a classic IPv6 node, receives the packet o When node N3, which is a non-SRv6 capable node, receives the
with hop-count = 1, it processes the hop count expiry. packet with hop-count = 1, it processes the hop-count expiry.
Specifically, the node N3 responses with the ICMPv6 message (Type: Specifically, the node N3 responds with the ICMPv6 message (Type:
"Time Exceeded", Code: "Hop limit exceeded in Transit"). The "Time Exceeded", Code: "Hop limit exceeded in Transit"). The
ICMPv6 response is IP routed. ICMPv6 response is IP routed.
o When node N3, which is a classic IPv6 node, receives the packet o When node N3, which is a non-SRv6 capable node, receives the
with hop-count > 1, it performs the standard IPv6 processing. packet with hop-count > 1, it performs the standard IPv6
Specifically, it forwards the traceroute probe based on DA processing. Specifically, it forwards the traceroute probe based
2001:db8:B:4:: in the IPv6 header. on DA 2001:db8:K:4:: in the IPv6 header.
o When node N4 receives the packet with DA set to the local SID o When node N4 receives the packet with DA set to the local SID
2001:db8:B:4::, it processes the END SID. 2001:db8:K:4::, it processes the END SID.
o If the target SID (2001:db8:B:4::) is not locally instantiated, o If the target SID (2001:db8:K:4::) is not locally instantiated and
the packet is discarded. does not represent a local interface, the packet is discarded.
o If the target SID (2001:db8:B:4::) is locally instantiated, the o If the target SID (2001:db8:K:4::) is locally instantiated or
node processes the upper layer header. As part of the upper layer represents a local interface, the node processes the upper layer
header processing node N4 responses with the ICMPv6 message (Type: header. As part of the upper layer header processing node N4
Destination unreachable, Code: Port Unreachable). The ICMPv6 responds with the ICMPv6 message (Type: Destination unreachable,
response is IP routed. Code: Port Unreachable). The ICMPv6 response is IP routed.
Figure 4 displays a sample traceroute output for this example. Figure 4 displays a sample traceroute output for this example.
> traceroute 2001:db8:B:4:C52:: via segment-list 2001:db8:B:2:C31:: > traceroute 2001:db8:K:4:X52:: via segment-list 2001:db8:K:2:X31::
Tracing the route to SID 2001:db8:B:4:C52:: Tracing the route to SID 2001:db8:K:4:X52::
1 2001:db8:1:2:21:: 0.512 msec 0.425 msec 0.374 msec 1 2001:db8:2:1:21:: 0.512 msec 0.425 msec 0.374 msec
DA: 2001:db8:B:2:C31::, DA: 2001:db8:K:2:X31::,
SRH:(2001:db8:B:4:C52::, 2001:db8:B:2:C31::; SL=1) SRH:(2001:db8:K:4:X52::, 2001:db8:K:2:X31::; SL=1)
2 2001:db8:2:3:31:: 0.721 msec 0.810 msec 0.795 msec 2 2001:db8:3:2:21:: 0.721 msec 0.810 msec 0.795 msec
DA: 2001:db8:B:4:C52::, DA: 2001:db8:K:4:X52::,
SRH:(2001:db8:B:4:C52::, 2001:db8:B:2:C31::; SL=0) SRH:(2001:db8:K:4:X52::, 2001:db8:K:2:X31::; SL=0)
3 2001:db8:3:4:41:: 0.921 msec 0.816 msec 0.759 msec 3 2001:db8:4:3:41:: 0.921 msec 0.816 msec 0.759 msec
DA: 2001:db8:B:4:C52::, DA: 2001:db8:K:4:X52::,
SRH:(2001:db8:B:4:C52::, 2001:db8:B:2:C31::; SL=0) SRH:(2001:db8:K:4:X52::, 2001:db8:K:2:X31::; SL=0)
Figure 4 A sample output for hop-by-hop traceroute to a SID Figure 4 A sample output for hop-by-hop traceroute to a SID
3.3. A Hybrid OAM Using O-flag 3.3. A Hybrid OAM Using O-flag
This section illustrates a hybrid OAM mechanism using the the O-flag. This section illustrates a hybrid OAM mechanism using the the O-flag.
Without loss of the generality, the illustration assumes N100 is a Without loss of the generality, the illustration assumes N100 is a
centralized controller. centralized controller.
The illustration is different than the In-situ OAM defined in [I.D- The illustration is different than the In-situ OAM defined in [I.D-
draft-ietf-ippm-ioam-data]. This is because In-situ OAM records draft-ietf-ippm-ioam-data]. This is because In-situ OAM records
operational and telemetry information in the packet as the packet operational and telemetry information in the packet as the packet
traverses a path between two points in the network [I.D-draft-ietf- traverses a path between two points in the network [I.D-draft-ietf-
ippm-ioam-data]. The illustration in this subsection does not ippm-ioam-data]. The illustration in this subsection does not
require the recording of OAM data in the packet. require the recording of OAM data in the packet.
The illustration does not assume any formats for exporting the data The illustration does not assume any formats for exporting the data
elements or the data elements that need to be exported. elements or the data elements that need to be exported. The
illustration assumes system clocks among all nodes in the SR domain
are synchronized.
Consider the example where the user wants to monitor sampled IPv4 VPN Consider the example where the user wants to monitor sampled IPv4 VPN
999 traffic going from CE1 to CE2 via a low latency SR policy P 999 traffic going from CE1 to CE2 via a low latency SR policy P
installed at Node N1. To exercise a low latency path, the SR Policy installed at Node N1. To exercise a low latency path, the SR Policy
P forces the packet via segments 2001:db8:B:2:C31:: and P forces the packet via segments 2001:db8:K:2:X31:: and
2001:db8:B:4:C52::. The VPN SID at N7 associated with VPN 999 is 2001:db8:K:4:X52::. The VPN SID at N7 associated with VPN 999 is
2001:db8:B:7:DT999::. 2001:db8:B:7:DT999:: is a USP SID. N1, N4, 2001:db8:K:7:DT999::. 2001:db8:K:7:DT999:: is a USP SID. N1, N4,
and N7 are capable of processing O-flag but N2 is not capable of and N7 are capable of processing O-flag but N2 is not capable of
processing O-flag. N100 is the centralized controller capable of processing O-flag. N100 is the centralized controller capable of
processing and correlating the copy of the packets sent from nodes processing and correlating the copy of the packets sent from nodes
N1, N4, and N7. N100 is aware of O-flag processing capabilities. N1, N4, and N7. N100 is aware of O-flag processing capabilities.
Controller N100 with the help from nodes N1, N4, N7 and implements a Controller N100 with the help from nodes N1, N4, N7 and implements a
hybrid OAM mechanism using the O-flag as follows: hybrid OAM mechanism using the O-flag as follows:
o A packet P1:(IPv4 header)(payload) is sent from CE1 to Node N1. o A packet P1:(IPv4 header)(payload) is sent from CE1 to Node N1.
o Node N1 steers the packet P1 through the Policy P. Based on a o Node N1 steers the packet P1 through the Policy P. Based on a
local configuration, Node N1 also implements logic to sample local configuration, Node N1 also implements logic to sample
traffic steered through policy P for hybrid OAM purposes. traffic steered through policy P for hybrid OAM purposes.
Specification for the sampling logic is beyond the scope of this Specification for the sampling logic is beyond the scope of this
document. Consider the case where packet P1 is classified as a document. Consider the case where packet P1 is classified as a
packet to be monitored via the hybrid OAM. Node N1 sets O-flag packet to be monitored via the hybrid OAM. Node N1 sets O-flag
during encapsulation required by policy P. As part of setting the during the encapsulation required by policy P. As part of setting
O-flag, node N1 also sends a timestamped copy of the packet P1: the O-flag, node N1 also sends a timestamped copy of the packet
(2001:db8:A:1::, 2001:db8:B:2:C31::) (2001:db8:B:7:DT999::, P1: (2001:db8:L:1::, 2001:db8:K:2:X31::) (2001:db8:K:7:DT999::,
2001:db8:B:4:C52::, 2001:db8:B:2:C31::; SL=2; O-flag=1; 2001:db8:K:4:X52::, 2001:db8:K:2:X31::; SL=2; O-flag=1;
NH=IPv4)(IPv4 header)(payload) to a local OAM process. The local NH=IPv4)(IPv4 header)(payload) to a local OAM process. The local
OAM process sends a full or partial copy of the packet P1 to the OAM process sends a full or partial copy of the packet P1 to the
controller N100. The OAM process includes the recorded timestamp, controller N100. The OAM process includes the recorded timestamp,
additional OAM information like incoming and outgoing interface, additional OAM information like incoming and outgoing interface,
etc. along with any applicable metadata. Node N1 forwards the etc. along with any applicable metadata. Node N1 forwards the
original packet towards the next segment 2001:db8:B:2:C31::. original packet towards the next segment 2001:db8:K:2:X31::.
o When node N2 receives the packet with O-flag set, it ignores the o When node N2 receives the packet with O-flag set, it ignores the
O-flag. This is because node N2 is not capable of processing the O-flag. This is because node N2 is not capable of processing the
O-flag. Node N2 performs the standard SRv6 SID and SRH O-flag. Node N2 performs the standard SRv6 SID and SRH
processing. Specifically, it executes the END.X behavior processing. Specifically, it executes the End.X behavior
(2001:db8:B:2:C31::) as described in [RFC8986] and forwards the indicated by the 2001:db8:K:2:X31:: SID as described in [RFC8986]
packet P1 (2001:db8:A:1::, 2001:db8:B:4:C52::) and forwards the packet P1 (2001:db8:L:1::, 2001:db8:K:4:X52::)
(2001:db8:B:7:DT999::, 2001:db8:B:4:C52::, 2001:db8:B:2:C31::; (2001:db8:K:7:DT999::, 2001:db8:K:4:X52::, 2001:db8:K:2:X31::;
SL=1; O-flag=1; NH=IPv4)(IPv4 header)(payload) over link 3 towards SL=1; O-flag=1; NH=IPv4)(IPv4 header)(payload) over link 3 towards
Node N3. Node N3.
o When node N3, which is a classic IPv6 node, receives the packet P1 o When node N3, which is a non-SRv6 capable node, receives the
, it performs the standard IPv6 processing. Specifically, it packet P1 , it performs the standard IPv6 processing.
forwards the packet P1 based on DA 2001:db8:B:4:C52:: in the IPv6 Specifically, it forwards the packet P1 based on DA
header. 2001:db8:K:4:X52:: in the IPv6 header.
o When node N4 receives the packet P1 (2001:db8:A:1::, o When node N4 receives the packet P1 (2001:db8:L:1::,
2001:db8:B:4:C52::) (2001:db8:B:7:DT999::, 2001:db8:B:4:C52::, 2001:db8:K:4:X52::) (2001:db8:K:7:DT999::, 2001:db8:K:4:X52::,
2001:db8:B:2:C31::; SL=1; O-flag=1; NH=IPv4)(IPv4 2001:db8:K:2:X31::; SL=1; O-flag=1; NH=IPv4)(IPv4
header)(payload), it processes the O-flag. As part of processing header)(payload), it processes the O-flag. As part of processing
the O-flag, it sends a timestamped copy of the packet to a local the O-flag, it sends a timestamped copy of the packet to a local
OAM process. Based on a local configuration, the local OAM OAM process. Based on a local configuration, the local OAM
process sends a full or partial copy of the packet P1 to the process sends a full or partial copy of the packet P1 to the
controller N100. The OAM process includes the recorded timestamp, controller N100. The OAM process includes the recorded timestamp,
additional OAM information like incoming and outgoing interface, additional OAM information like incoming and outgoing interface,
etc. along with any applicable metadata. Node N4 performs the etc. along with any applicable metadata. Node N4 performs the
standard SRv6 SID and SRH processing on the original packet P1. standard SRv6 SID and SRH processing on the original packet P1.
Specifically, it executes the END.X behavior (2001:db8:B:4:C52::) Specifically, it executes the End.X behavior indicated by the
and forwards the packet P1 (2001:db8:A:1::, 2001:db8:B:7:DT999::) 2001:db8:K:4:X52:: SID and forwards the packet P1 (2001:db8:L:1::,
(2001:db8:B:7:DT999::, 2001:db8:B:4:C52::, 2001:db8:B:2:C31::; 2001:db8:K:7:DT999::) (2001:db8:K:7:DT999::, 2001:db8:K:4:X52::,
SL=0; O-flag=1; NH=IPv4)(IPv4 header)(payload) over link 10 2001:db8:K:2:X31::; SL=0; O-flag=1; NH=IPv4)(IPv4 header)(payload)
towards Node N5. over link 10 towards Node N5.
o When node N5, which is a classic IPv6 node, receives the packet o When node N5, which is a non-SRv6 capable node, receives the
P1, it performs the standard IPv6 processing. Specifically, it packet P1, it performs the standard IPv6 processing.
forwards the packet based on DA 2001:db8:B:7:DT999:: in the IPv6 Specifically, it forwards the packet based on DA
header. 2001:db8:K:7:DT999:: in the IPv6 header.
o When node N7 receives the packet P1 (2001:db8:A:1::, o When node N7 receives the packet P1 (2001:db8:L:1::,
2001:db8:B:7:DT999::) (2001:db8:B:7:DT999::, 2001:db8:B:4:C52::, 2001:db8:K:7:DT999::) (2001:db8:K:7:DT999::, 2001:db8:K:4:X52::,
2001:db8:B:2:C31::; SL=0; O-flag=1; NH=IPv4)(IPv4 2001:db8:K:2:X31::; SL=0; O-flag=1; NH=IPv4)(IPv4
header)(payload), it processes the O-flag. As part of processing header)(payload), it processes the O-flag. As part of processing
the O-flag, it sends a timestamped copy of the packet to a local the O-flag, it sends a timestamped copy of the packet to a local
OAM process. The local OAM process sends a full or partial copy OAM process. The local OAM process sends a full or partial copy
of the packet P1 to the controller N100. The OAM process includes of the packet P1 to the controller N100. The OAM process includes
the recorded timestamp, additional OAM information like incoming the recorded timestamp, additional OAM information like incoming
and outgoing interface, etc. along with any applicable metadata. and outgoing interface, etc. along with any applicable metadata.
Node N4 performs the standard SRv6 SID and SRH processing on the Node N7 performs the standard SRv6 SID and SRH processing on the
original packet P1. Specifically, it executes the VPN SID original packet P1. Specifically, it executes the VPN SID
(2001:db8:B:7:DT999::) and based on lookup in table 100 forwards indicated by the 2001:db8:K:7:DT999:: SID and based on lookup in
the packet P1 (IPv4 header)(payload) towards CE 2. table 100 forwards the packet P1 (IPv4 header)(payload) towards CE
2.
o The controller N100 processes and correlates the copy of the o The controller N100 processes and correlates the copy of the
packets sent from nodes N1, N4 and N7 to find segment-by-segment packets sent from nodes N1, N4 and N7 to find segment-by-segment
delays and provide other hybrid OAM information related to packet delays and provide other hybrid OAM information related to packet
P1. P1. For segment-by-segment delay computation, it is assumed that
clock are synchronized time across the SR domain.
o The process continues for any other sampled packets. o The process continues for any other sampled packets.
3.4. Monitoring of SRv6 Paths 3.4. Monitoring of SRv6 Paths
In the recent past, network operators demonstrated interest in In the recent past, network operators demonstrated interest in
performing network OAM functions in a centralized manner. [RFC8403] performing network OAM functions in a centralized manner. [RFC8403]
describes such a centralized OAM mechanism. Specifically, the describes such a centralized OAM mechanism. Specifically, the
document describes a procedure that can be used to perform path document describes a procedure that can be used to perform path
continuity check between any nodes within an SR domain from a continuity check between any nodes within an SR domain from a
centralized monitoring system. However, the document focuses on SR centralized monitoring system. However, the document focuses on SR
networks with MPLS data plane. This document describes how the networks with MPLS data plane. This document describes how the
concept can be used to perform path monitoring in an SRv6 network concept can be used to perform path monitoring in an SRv6 network
from a centralized controller. from a centralized controller.
In the reference topology in Figure 1, N100 uses an IGP protocol like In the reference topology in Figure 1, N100 uses an IGP protocol like
OSPF or ISIS to get the topology view within the IGP domain. N100 OSPF or IS-IS to get the topology view within the IGP domain. N100
can also use BGP-LS to get the complete view of an inter-domain can also use BGP-LS to get the complete view of an inter-domain
topology. The controller leverages the visibility of the topology to topology. The controller leverages the visibility of the topology to
monitor the paths between the various endpoints. monitor the paths between the various endpoints.
The controller N100 advertises an END SID [RFC8986] The controller N100 advertises an END SID [RFC8986]
2001:db8:B:100:1::. To monitor any arbitrary SRv6 paths, the 2001:db8:K:100:1::. To monitor any arbitrary SRv6 paths, the
controller can create a loopback probe that originates and terminates controller can create a loopback probe that originates and terminates
on Node N100. To distinguish between a failure in the monitored path on Node N100. To distinguish between a failure in the monitored path
and loss of connectivity between the controller and the network, Node and loss of connectivity between the controller and the network, Node
N100 runs a suitable mechanism to monitor its connectivity to the N100 runs a suitable mechanism to monitor its connectivity to the
monitored network. monitored network.
The loopback probes are exemplified using an example where controller The loopback probes are exemplified using an example where controller
N100 needs to verify a segment list <2001:db8:B:2:C31::, N100 needs to verify a segment list <2001:db8:K:2:X31::,
2001:db8:B:4:C52::>: 2001:db8:K:4:X52::>:
o N100 generates an OAM packet (2001:db8:A:100::, o N100 generates an OAM packet (2001:db8:L:100::,
2001:db8:B:2:C31::)(2001:db8:B:100:1::, 2001:db8:B:4:C52::, 2001:db8:K:2:X31::)(2001:db8:K:100:1::, 2001:db8:K:4:X52::,
2001:db8:B:2:C31::, SL=2)(OAM Payload). The controller routes the 2001:db8:K:2:X31::, SL=2)(OAM Payload). The controller routes the
probe packet towards the first segment, which is probe packet towards the first segment, which is
2001:db8:B:2:C31::. 2001:db8:K:2:X31::.
o Node N2 executes the END.X behavior (2001:db8:B:2:C31::) and o Node N2 executes the End.X behavior indicated by the
forwards the packet (2001:db8:A:100::, 2001:db8:K:2:X31:: SID and forwards the packet (2001:db8:L:100::,
2001:db8:B:4:C52::)(2001:db8:B:100:1::, 2001:db8:B:4:C52::, 2001:db8:K:4:X52::)(2001:db8:K:100:1::, 2001:db8:K:4:X52::,
2001:db8:B:2:C31::, SL=1)(OAM Payload) on link3 to N3. 2001:db8:K:2:X31::, SL=1)(OAM Payload) on link3 to N3.
o Node N3, which is a classic IPv6 node, performs the standard IPv6 o Node N3, which is a non-SRv6 capable node, performs the standard
processing. Specifically, it forwards the packet based on the DA IPv6 processing. Specifically, it forwards the packet based on
2001:db8:B:4:C52:: in the IPv6 header. the DA 2001:db8:K:4:X52:: in the IPv6 header.
o Node N4 executes the END.X behavior (2001:db8:B:4:C52::) and o Node N4 executes the End.X behavior indicated by the
forwards the packet (2001:db8:A:100::, 2001:db8:K:4:X52:: SID and forwards the packet (2001:db8:L:100::,
2001:db8:B:100:1::)(2001:db8:B:100:1::, 2001:db8:B:4:C52::, 2001:db8:K:100:1::)(2001:db8:K:100:1::, 2001:db8:K:4:X52::,
2001:db8:B:2:C31::, SL=0)(OAM Payload) on link10 to N5. 2001:db8:K:2:X31::, SL=0)(OAM Payload) on link10 to N5.
o Node N5, which is a classic IPv6 node, performs the standard IPv6 o Node N5, which is a non-SRv6 capable node, performs the standard
processing. Specifically, it forwards the packet based on the DA IPv6 processing. Specifically, it forwards the packet based on
2001:db8:B:100:1:: in the IPv6 header. the DA 2001:db8:K:100:1:: in the IPv6 header.
o Node N100 executes the standard SRv6 END behavior. It o Node N100 executes the standard SRv6 END behavior. It
decapsulates the header and consume the probe for OAM processing. decapsulates the header and consume the probe for OAM processing.
The information in the OAM payload is used to detect any missing The information in the OAM payload is used to detect any missing
probes, round trip delay, etc. probes, round trip delay, etc.
The OAM payload type or the information carried in the OAM probe is a The OAM payload type or the information carried in the OAM probe is a
local implementation decision at the controller and is outside the local implementation decision at the controller and is outside the
scope of this document. scope of this document.
4. Implementation Status 4. Implementation Status
This section is to be removed prior to publishing as an RFC. This section is to be removed prior to publishing as an RFC.
See [I-D.matsushima-spring-srv6-deployment-status] for updated See [I-D.matsushima-spring-srv6-deployment-status] for updated
deployment and interoperability reports. deployment and interoperability reports.
5. Security Considerations 5. Security Considerations
This document does not define any new protocol extensions and relies
on existing procedures defined for ICMPv6.
[RFC8754] defines the notion of an SR domain and use of SRH within [RFC8754] defines the notion of an SR domain and use of SRH within
the SR domain. The use of OAM procedures described in this document the SR domain. The use of OAM procedures described in this document
is restricted to an SR domain. For example, similar to the SID is restricted to an SR domain. For example, similar to the SID
manipulation, O-flag manipulation is not considered as a threat manipulation, O-flag manipulation is not considered as a threat
within the SR domain. Procedures for securing an SR domain are within the SR domain. Procedures for securing an SR domain are
defined the section 5.1 and section 7 of [RFC8754]. defined the section 5.1 and section 7 of [RFC8754].
As noted in section 7.1 of [RFC8754], compromised nodes within the SR As noted in section 7.1 of [RFC8754], compromised nodes within the SR
domain may mount attacks. The O-flag may be set by an attacking node domain may mount attacks. The O-flag may be set by an attacking node
attempting a denial-of-service attack on the OAM process at the attempting a denial-of-service attack on the OAM process at the
segment endpoint node. An implementation correctly implementing the segment endpoint node. An implementation correctly implementing the
rate limiting in section 2.1.1 is not susceptible to that denial-of- rate limiting in section 2.1.1 is not susceptible to that denial-of-
service attack. Additionally, SRH Flags are protected by the HMAC service attack. Additionally, SRH Flags are protected by the HMAC
TLV, as described in Section 2.1.2.1 of [RFC8754]. TLV, as described in Section 2.1.2.1 of [RFC8754]. Once an HMAC is
generated for a segment list with the O-flag set, it can be used for
an arbitrary amount of traffic using that segment list with O-flag
set.
The security properties of the channel used to send exported packets
marked by the O-flag will depend on the specific OAM processes used.
An on-path attacker able to observe this OAM channel could conduct
traffic analysis, or potentially eavesdropping (depending on the OAM
configuration), of this telemetry for the entire SR domain from such
a vantage point.
This document does not impose any additional security challenges to This document does not impose any additional security challenges to
be considered beyond security threats described in [RFC4884], be considered beyond security threats described in [RFC4884],
[RFC4443], [RFC0792], and [RFC8754]. [RFC4443], [RFC0792], [RFC8754] and [RFC8986].
6. IANA Considerations 6. Privacy Considerations
The per-packet marking capabilities of the O-flag provides a granular
mechanism to collect telemetry. When this collection is deployed by
an operator with knowledge and consent of the users, it will enable a
variety of diagnostics and monitoring to support the OAM and security
operations use cases needed for resilient network operations.
However, this collection mechanism will also provide an explicit
protocol mechanism to operators for surveillance and pervasive
monitoring use cases done contrary to the user's consent.
7. IANA Considerations
This document requests that IANA allocate the following registration This document requests that IANA allocate the following registration
in the "Segment Routing Header Flags" sub-registry for the "Internet in the "Segment Routing Header Flags" sub-registry for the "Internet
Protocol Version 6 (IPv6) Parameters" registry maintained by IANA: Protocol Version 6 (IPv6) Parameters" registry maintained by IANA:
+-------+------------------------------+---------------+ +-------+------------------------------+---------------+
| Bit | Description | Reference | | Bit | Description | Reference |
+=======+==============================+===============+ +=======+==============================+===============+
| 2 | O-flag | This document | | 2 | O-flag | This document |
+-------+------------------------------+---------------+ +-------+------------------------------+---------------+
7. Acknowledgements 8. Acknowledgements
The authors would like to thank Joel M. Halpern, Greg Mirsky, Bob The authors would like to thank Joel M. Halpern, Greg Mirsky, Bob
Hinden, Loa Andersson, Gaurav Naik, Ketan Talaulikar and Haoyu Song Hinden, Loa Andersson, Gaurav Naik, Ketan Talaulikar and Haoyu Song
for their review comments. for their review comments.
8. Contributors 9. Contributors
The following people have contributed to this document: The following people have contributed to this document:
Robert Raszuk Robert Raszuk
Bloomberg LP Bloomberg LP
Email: robert@raszuk.net Email: robert@raszuk.net
John Leddy John Leddy
Individual Individual
Email: john@leddy.net Email: john@leddy.net
skipping to change at page 20, line 38 skipping to change at page 21, line 21
Email: ddukes@cisco.com Email: ddukes@cisco.com
Cheng Li Cheng Li
Huawei Huawei
Email: chengli13@huawei.com Email: chengli13@huawei.com
Faisal Iqbal Faisal Iqbal
Individual Individual
Email: faisal.ietf@gmail.com Email: faisal.ietf@gmail.com
9. References 10. References
9.1. Normative References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[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>.
skipping to change at page 21, line 26 skipping to change at page 22, line 5
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>. <https://www.rfc-editor.org/info/rfc8754>.
[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer, [RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6 D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986, (SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021, DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>. <https://www.rfc-editor.org/info/rfc8986>.
9.2. Informative References 10.2. Informative References
[I-D.gandhi-spring-stamp-srpm] [I-D.gandhi-spring-stamp-srpm]
Gandhi, R., Filsfils, C., Voyer, D., Chen, M., Janssens, Gandhi, R., Filsfils, C., Voyer, D., Chen, M., Janssens,
B., and R. Foote, "Performance Measurement Using Simple B., and R. Foote, "Performance Measurement Using Simple
TWAMP (STAMP) for Segment Routing Networks", draft-gandhi- TWAMP (STAMP) for Segment Routing Networks", draft-gandhi-
spring-stamp-srpm-06 (work in progress), April 2021. spring-stamp-srpm-07 (work in progress), July 2021.
[I-D.ietf-ippm-ioam-data] [I-D.ietf-ippm-ioam-data]
Brockners, F., Bhandari, S., and T. Mizrahi, "Data Fields Brockners, F., Bhandari, S., and T. Mizrahi, "Data Fields
for In-situ OAM", draft-ietf-ippm-ioam-data-11 (work in for In-situ OAM", draft-ietf-ippm-ioam-data-11 (work in
progress), November 2020. progress), November 2020.
[I-D.matsushima-spring-srv6-deployment-status] [I-D.matsushima-spring-srv6-deployment-status]
Matsushima, S., Filsfils, C., Ali, Z., Li, Z., and K. Matsushima, S., Filsfils, C., Ali, Z., Li, Z., and K.
Rajaraman, "SRv6 Implementation and Deployment Status", Rajaraman, "SRv6 Implementation and Deployment Status",
draft-matsushima-spring-srv6-deployment-status-11 (work in draft-matsushima-spring-srv6-deployment-status-11 (work in
 End of changes. 103 change blocks. 
278 lines changed or deleted 303 lines changed or added

This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/