Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi...
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Transcript of Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi...
![Page 1: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/1.jpg)
Advertising Generic Information in IS-IS
draft-ietf-isis-genapp-00.txtLes Ginsberg
Stefano Previdi
Mike Shand
![Page 2: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/2.jpg)
Changes since previous version
• Now a WG document
• Standards track
• Applicability statement
![Page 3: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/3.jpg)
Applicability Statement
“The GENINFO TLV supports the advertisement of application specific information in IS-IS LSPs which is not directly related to the operation of the IS-IS protocol. Information which is not directly used by the IS-IS Decision process falls into this category. The Decision Process is defined by [ISO10589] and extended by [RFC1195] and [RFC3906].”
![Page 4: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/4.jpg)
Applicability Statement
• May be interpreted to cover existing information
• Migration to use of GENAPP is seen as desirable
• WG is the authority
![Page 5: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/5.jpg)
What existing info MIGHT
be candidates for GENAPP?
• TE/G-MPLS sub-TLV info (from TLVs 22/23/222/223)
• TE Mesh Group sub-TLV (TLV 242)
• PCE sub-TLV info (TLV 242)
![Page 6: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/6.jpg)
Ready for Last Call
![Page 7: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/7.jpg)
IS-IS and BFD
draft-ietf-isis-bfd-tlv-00.txtChris Hopps
Les Ginsberg
![Page 8: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/8.jpg)
Changes since previous version
• Now a WG document
• Standards track
• TLV now includes MTID
![Page 9: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/9.jpg)
Problem Statement
• BFD used to detect IPv4/IPv6 forwarding failures
• IS-IS PDUs do not always share fate with IP packets
• Adjacencies may be established even when IP forwarding problems are detectable
![Page 10: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/10.jpg)
A BIP
IS-IS
1. IS-IS PDUs exchanged
2. Adjacency UP
3. BFD session requested (neighbor IP address)
If BFD session doesn’t come up could be:
• IP forwarding failure
• No BFD Config/Support
![Page 11: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/11.jpg)
Advertise support for BFD in IIHsType 139 (proposed) Length # of octets in the value field (1 to 255) Value: No. of octets +-----------------------------+ |R|R|R|R| MTID | 2 +-----------------------------+ | NLPID | 1 +-----------------------------+ : : +-----------------------------+ |R|R|R|R| MTID | 2 +-----------------------------+ | NLPID | 1 +------------------------------+
![Page 12: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/12.jpg)
Why was MTID Added?
• BFD sessions apply to specific topologies
• NLPIDs are not SAFI specific
![Page 13: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/13.jpg)
When BFD is supported by both neighbors…
• Hold adjacency in Init state until BFD session is UP
• Bring adjacency down when BFD session goes down
• P2P – 3 way state is DOWN when BFD is down
• LAN – omit neighbor MAC address when BFD is down
![Page 14: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/14.jpg)
Determining when new rules apply
For each MTID/NLPID shared by the neighbors, if BFD support is configured for both neighbors, BFD session must be UP to use that topology
At least one topology must be “useable” in order for adjacency to come up
![Page 15: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/15.jpg)
A BIP
IS-IS
MTID: 0(IPv4), 2(IPv6)
BFD: 0/IPv4, 2/IPv6
MTID: 0 (IPv4)
BFD: 0/IPv4
IPv4 BFD Session MUST be UP before adjacency comes up.
![Page 16: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/16.jpg)
A BIP
IS-IS
MTID: 0(IPv4), 0(IPv6)
BFD: 0/IPv4, 2/IPv6
MTID: 0 (IPv4,IPv6)
BFD: 0/IPv4
Single Topology/Multiple AFIs
IPv4 Session MUST be UP before adjacency comes up.
![Page 17: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/17.jpg)
A BIP
IS-IS
MTID: 0 (IPv4), 2 (IPv6)
BFD: 0/IPv4, 2/IPv6
MTID: 0 (IPv4), 2 (IPv6)
BFD: 0/IPv4
Multi-topology (one AFI/topology)
Normal adjacency establishment rules.
IPv4 BFD Session MUST be UP for MTID #0 to be useable.
![Page 18: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/18.jpg)
Transition – enable BFD
Detected by addition of NLPID in BFD-TLV
For existing adjacencies, do not update hold time on receipt of IIH until BFD session is UP
![Page 19: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/19.jpg)
A BIP
IS-IS
MTID: 0 (IPv4)
BFD: 0/IPv4
MTID: 0 (IPv4)
BFD: 0/IPv4
1. Adjacency is Up
2. B configures IPv4 BFD support
3. IIH from B includes BFD-TLV for MTID 0/IPv4 – hold time not updated
4. BFD session comes up
5. Normal hold time update resumes
![Page 20: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/20.jpg)
Transition – disable BFD
Detected by transition of BFD session state to admin down
For existing adjacencies, do not update hold time on receipt of IIH until corresponding NLPID is no longer advertised in BFD-TLV
![Page 21: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/21.jpg)
A BIP
IS-IS
MTID: 0 (IPv4)
BFD: 0/IPv4
MTID: 0 (IPv4)
BFD: 0/IPv4
1. Adjacency is Up/BFD session Up
2. B deconfigures IPv4 BFD support
3. IPv4 BFD session admin down on A
4. IIH from B has no BFD-TLV for MTID 0/IPv4
5. Normal hold time update resumes
![Page 22: Advertising Generic Information in IS-IS draft-ietf-isis-genapp-00.txt Les Ginsberg Stefano Previdi Mike Shand.](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e2ab550346935c8b5705/html5/thumbnails/22.jpg)
Questions?