draft-ietf-idr-bgp-enhanced-route-refresh-04.txt   draft-ietf-idr-bgp-enhanced-route-refresh-05.txt 
Network Working Group K. Patel IDR K. Patel
Internet Draft E. Chen Internet-Draft E. Chen
Intended Status: Standards Track B. Venkatachalapathy Intended status: Standards Track B. Venkatachalapathy
Expiration Date: December 25, 2013 Cisco Systems Expires: June 12, 2014 Cisco Systems
June 24, 2013 December 9, 2013
Enhanced Route Refresh Capability for BGP-4 Enhanced Route Refresh Capability for BGP-4
draft-ietf-idr-bgp-enhanced-route-refresh-04.txt draft-ietf-idr-bgp-enhanced-route-refresh-05.txt
Status of this Memo Abstract
This Internet-Draft is submitted to IETF in full conformance with the In this document we enhance the existing BGP route refresh mechanisms
to provide for the demarcation of the beginning and the ending of a
route refresh. The enhancement can be used to facilitate correction
of BGP RIB inconsistencies in a non-disruptive manner.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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draft-ietf-idr-bgp-enhanced-route-refresh-04.txt Table of Contents
Abstract
In this document we enhance the existing BGP route refresh mechanisms 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
to provide for the demarcation of the beginning and the ending of a 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2
route refresh. The enhancement can be used to facilitate on-line, 3. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 2
non-disruptive consistency validations of BGP routing updates. 3.1. Enhanced Route Refresh Capability . . . . . . . . . . . . 2
3.2. Subtypes for ROUTE-REFRESH Message . . . . . . . . . . . 3
4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Security Considerations . . . . . . . . . . . . . . . . . . . 5
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
9. Normative References . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
It is sometimes necessary to perform routing consistency validations It is sometimes necessary to perform routing consistency validations
such as checking for possible missing withdraws between BGP speakers such as checking for possible missing withdraws between BGP speakers
[RFC4271]. Currently such validations typically involve off-line, [RFC4271]. Currently such validations typically involve off-line,
manual operations which can be tedious and time consuming. manual operations which can be tedious and time consuming.
In this document we enhance the existing BGP route refresh mechanisms In this document we enhance the existing BGP route refresh mechanisms
[RFC2918] to provide for the demarcation of the beginning and the [RFC2918] to provide for the demarcation of the beginning and the
ending of a route refresh (which refers to the complete re- ending of a route refresh (which refers to the complete re-
advertisement of the Adj-RIB-Out to a peer, subject to routing advertisement of the Adj-RIB-Out to a peer, subject to routing
policies). The enhancement can be used to facilitate on-line, non- policies). The enhancement can be used to facilitate on-line, non-
disruptive consistency validation of BGP routing updates. disruptive consistency validation of BGP routing updates.
1.1. Specification of Requirements 2. 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", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to
document are to be interpreted as described in [RFC2119]. be interpreted as described in [RFC2119] only when they appear in all
upper case. They may also appear in lower or mixed case as English
words, without any normative meaning.
2. Protocol Extensions 3. Protocol Extensions
The BGP protocol extensions introduced in this document include the The BGP protocol extensions introduced in this document include the
definition of a new BGP capability, named "Enhanced Route Refresh definition of a new BGP capability, named "Enhanced Route Refresh
Capability", and the specification of the message subtypes for the Capability", and the specification of the message subtypes for the
ROUTE-REFRESH message. ROUTE-REFRESH message.
2.1. Enhanced Route Refresh Capability 3.1. Enhanced Route Refresh Capability
The "Enhanced Route Refresh Capability" is a new BGP capability The "Enhanced Route Refresh Capability" is a new BGP capability
[RFC5492]. The Capability Code for this capability is specified in [RFC5492]. IANA has assigned a Capability Code of 70 for this
the IANA Considerations section of this document. The Capability capability . The Capability Length field of this capability is zero.
Length field of this capability is zero.
By advertising this capability to a peer, a BGP speaker conveys to By advertising this capability to a peer, a BGP speaker conveys to
the peer that the speaker supports the message subtypes for the the peer that the speaker supports the message subtypes for the
ROUTE-REFRESH message and the related procedures described in this ROUTE-REFRESH message and the related procedures described in this
draft-ietf-idr-bgp-enhanced-route-refresh-04.txt
document. document.
2.2. Subtypes for ROUTE-REFRESH Message 3.2. Subtypes for ROUTE-REFRESH Message
The "Reserved" field of the ROUTE-REFRESH message specified in The "Reserved" field of the ROUTE-REFRESH message specified in
[RFC2918] is re-defined as the "Message Subtype" with the following [RFC2918] is re-defined as the "Message Subtype" with the following
values: values:
0 - Normal route refresh request [RFC2918] 0 - Normal route refresh request [RFC2918]
with/without ORF [RFC5291] with/without ORF [RFC5291]
1 - Demarcation of the beginning of a route refresh 1 - Demarcation of the beginning of a route refresh operation.
2 - Demarcation of the ending of a route refresh Also known as a "BoRR message" or just a "BoRR".
2 - Demarcation of the ending of a route refresh operation.
Also known as a "EoRR message" or just a "EoRR".
The use of the message subtypes is described in the Operations The remaining values of the message subtypes are reserved for future
section. use. The use of the new message subtypes is described in the
Operations section.
3. Operations 4. Operation
A BGP speaker that support the message subtypes for the ROUTE-REFRESH A BGP speaker that supports the message subtypes for the ROUTE-
message and the related procedures SHOULD advertise the "Enhanced REFRESH message and the related procedures SHOULD advertise the
Route Refresh Capability". "Enhanced Route Refresh Capability".
The following procedures are applicable only if a BGP speaker has The following procedures are applicable only if a BGP speaker has
received the "Enhanced Route Refresh Capability" from a peer. received the "Enhanced Route Refresh Capability" from a peer.
Before the speaker starts a route refresh that is either initiated Before the speaker starts a route refresh that is either initiated
locally, or in response to a "normal route refresh request" from the locally, or in response to a "normal route refresh request" from the
peer, the speaker MUST send a ROUTE-REFRESH message with the peer, the speaker MUST send a BoRR message. After the speaker
specified message subtype to mark the beginning of the route refresh. completes the re-advertisement of the entire Adj-RIB-Out to the peer,
After the speaker completes the re-advertisement of the entire Adj- it MUST send an EoRR message.
RIB-Out to the peer, it MUST send a ROUTE-REFRESH message with the
specified message subtype to mark the ending of the route refresh.
Conceptually the "entire ADJ-RIB-Out" for a peer in this section Conceptually the "entire Adj-RIB-Out" for a peer in this section
refers to all the route entries in the "ADJ-RIB-Out" for the peer at refers to all the route entries in the "Adj-RIB-Out" for the peer at
the start of the route refresh. When a route entry in the "ADJ-RIB- the start of the route refresh operation. These route entries
Out" changes, the advertisement of the modified route entry (instead comprise of both, the reachability as well as unreachability
of the snapshot entry) would suffice. information. When a route entry in the "ADJ-RIB-Out" changes, only
the modified route entry needs to be advertised.
In processing a ROUTE-REFRESH message from a peer, the BGP speaker In processing a ROUTE-REFRESH message from a peer, the BGP speaker
MUST examine the "message subtype" field of the message and take the MUST examine the "message subtype" field of the message and take the
appropriate actions. The BGP speaker SHALL use the demarcations of appropriate actions. The message processing rules for ROUTE-REFRESH
the beginning and the ending of a route refresh to perform message with subtype of 0 are described in [RFC2918] and [RFC5291].
consistency validations of the updates received from the peer. All A BGP speaker can receive a BoRR message from a peer at anytime,
either as a result of a peer responding to a ROUTE-REFESH message, or
draft-ietf-idr-bgp-enhanced-route-refresh-04.txt as a result of a peer unilaterally initiating a route refresh. When
a BGP speaker receives a BoRR message from a peer, it MUST mark all
the routes with the given <AFI, SAFI> from that peer as stale. As it
receives routes from its peer's subsequent Adj-RIB-Out re-
advertisement, these replace any corresponding stale routes. When a
BGP speaker receives an EoRR message from a peer, it MUST immediately
remove any routes from the peer that are still marked as stale for
that <AFI, SAFI>. Such purged routes MAY be logged for future
analysis.
the routes that were not re-advertised in the route refresh MUST be An implementation MAY impose a locally configurable upper bound on
purged, and SHOULD be logged for further analysis. how long it would retain any stale routes. Once the upper bound is
reached, the implementation MAY remove any routes from the peer that
are still marked as stale for that <AFI, SAFI> without waiting for an
EoRR message.
4. Error Handling 5. Error Handling
This document defines a new NOTIFICATION error code: This document defines a new NOTIFICATION error code:
Error Code Symbolic Name Error Code Symbolic Name
<TBD> ROUTE-REFRESH Message Error TBD ROUTE-REFRESH Message Error
The following error subcodes are defined as well: The following error subcodes are defined as well:
Subcode Symbolic Name Subcode Symbolic Name
1 Invalid Message Length 1 Invalid Message Length
The error handling specified in this section is applicable only when The error handling specified in this section is applicable only when
a BGP speaker has received the "Enhanced Route Refresh Capability" a BGP speaker has received the "Enhanced Route Refresh Capability"
from a peer. from a peer.
When the BGP speaker detects an error while processing a ROUTE- When the BGP speaker detects an error while processing a ROUTE-
REFRESH message with a non-zero "Message Subtype" field, it MUST send REFRESH message with a non-zero "Message Subtype" field, it MUST send
a NOTIFICATION message with Error Code "ROUTE-REFRESH Message Error". a NOTIFICATION message with Error Code "ROUTE-REFRESH Message Error".
The Data field of the NOTIFICATION message MUST contain the complete The Data field of the NOTIFICATION message MUST contain the complete
ROUTE-REFRESH message. ROUTE-REFRESH message.
If the length, excluding the fixed-size message header, of the ROUTE- If the length, excluding the fixed-size message header, of the ROUTE-
REFRESH message with Message Subtype 1 and 2 is not 4, then the error REFRESH message with Message Subtype 1 and 2 is not 4, then the error
subcode is set to "Invalid Message Length". subcode is set to "Invalid Message Length".
5. IANA Considerations When the BGP speaker receives a ROUTE-REFRESH message with an invalid
Subtype, it SHOULD log an error and ignore the received ROUTE-REFRESH
message.
6. IANA Considerations
This document defines the Enhanced Route Refresh Capability for BGP. This document defines the Enhanced Route Refresh Capability for BGP.
The Capability Code 70 has been assigned by the IANA. The Capability Code 70 has been assigned by the IANA. This document
also defines two new subcodes for the Route Refresh message. They
need to be registered with the IANA. We request IANA to create a new
registry for the Route Refresh message subcodes as follows:
Under "Border Gateway Protocol (BGP) Parameters":
Registry: "BGP Route Refresh Subcodes"
Reference: [draft-ietf-idr-bgp-enhanced-refresh-05.txt]
Registration Procedure(s): Values 0-127 Standards Action, values
128-254 First Come, First Served, Value 255 reserved
Value Code Reference
0 Route-Refresh [RFC2918], [RFC5291]
1 BoRR [draft-ietf-idr-bgp-enhanced-refresh-05.txt]
2 EoRR [draft-ietf-idr-bgp-enhanced-refresh-05.txt]
255 Reserved
In addition, this document defines an NOTIFICATION error code and In addition, this document defines an NOTIFICATION error code and
several error subcodes for the ROUTE-REFRESH message. They need to several error subcodes for the ROUTE-REFRESH message. The
be registered with the IANA. NOTIFICATION error code need to be registered with the IANA. We
request IANA to create a new registry for the error subcodes as
follows:
draft-ietf-idr-bgp-enhanced-route-refresh-04.txt Under "BGP Error Subcodes":
Registry: "BGP ROUTE-REFRESH Message Error subcodes"
Reference: [draft-ietf-idr-bgp-enhanced-refresh-05.txt]
Registration Procedure(s): Values 0-127 Standards Action, values
128-255 First Come, First Served
6. Security Considerations Value Code Reference
0 Reserved
1 Invalid Message Length [draft-ietf-idr-bgp-enhanced-refresh-05.txt]
7. Security Considerations
This extension to BGP does not change the underlying security issues. This extension to BGP does not change the underlying security issues.
7. Acknowledgments 8. Acknowledgements
The authors would like to thank Pedro Marques, Pradosh Mohapatra, The authors would like to thank Pedro Marques, Pradosh Mohapatra,
Robert Raszuk, Pranav Mehta, and Shyam Sethuram for discussions and Robert Raszuk, Pranav Mehta, and Shyam Sethuram, Bruno Decraene,
review. The authors would like to thank Martin Djernaes, Jeff haas, Martin Djernaes, Jeff haas, Ilya Varlashkin, Rob Shakir, Paul Jakma,
Ilya Varlashkin, Rob Shakir, Paul Jakma, Jie Dong, Qing Zeng, Albert Jie Dong, Qing Zeng, Albert Tian, and Jakob Heitz for their review
Tian, and Jakob Heitz for their review and comments. and comments. The authors would like to thank John Scudder for the
review and contribution to this document.
8. Normative References 9. Normative References
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Border Gateway Protocol 4 (BGP-4)", RFC 4271, January Requirement Levels", BCP 14, RFC 2119, March 1997.
2006.
[RFC2918] Chen, E., "Route Refresh Capability for BGP-4", [RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918,
RFC 2918, September 2000. September 2000.
[RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
with BGP-4", RFC 5492, February 2009. Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC5291] Chen, E., and Rekhter, Y., "Outbound Route Filtering [RFC5291] Chen, E. and Y. Rekhter, "Outbound Route Filtering
Capability for BGP-4", RFC 5291, August 2008. Capability for BGP-4", RFC 5291, August 2008.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement
Requirement Levels", BCP 14, RFC 2119, March 1997. with BGP-4", RFC 5492, February 2009.
9. Authors' Addresses Authors' Addresses
Keyur Patel Keyur Patel
Cisco Systems Cisco Systems
170 W. Tasman Drive
San Jose, CA 95124 95134
USA
Email: keyupate@cisco.com Email: keyupate@cisco.com
Enke Chen Enke Chen
Cisco Systems Cisco Systems
170 W. Tasman Drive
San Jose, CA 95124 95134
USA
Email: enkechen@cisco.com Email: enkechen@cisco.com
Balaji Venkatachalapathy Balaji Venkatachalapathy
Cisco Systems Cisco Systems
170 W. Tasman Drive
draft-ietf-idr-bgp-enhanced-route-refresh-04.txt San Jose, CA 95124 95134
USA
Email: bvenkata@cisco.com Email: bvenkata@cisco.com
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