Session Date/Time: 09 Nov 2022 09:30

lsr

Summary

The LSR working group met at IETF 115. The meeting covered several key topics including the status of existing drafts, updates to Yang models, ospf generalized transport, prefix unreachability, reverse affinity, loop detection, and flowspec distribution. A key theme was finding ways to accelerate the publication of Yang models and concerns over introducing complexity into IGP protocols.

Key Discussion Points

Yang Model Publication: Discussion of the delays in publishing Yang models, specifically the BFD model, and the need to expedite the process to compete with OpenConfig. It was proposed that incorporating simpler Yang models directly into the protocol extension drafts could be more efficient.
OSPF Generalized Transport: Presentation of the OSPF Generalized Transport (GT) draft, now renamed, which aims to provide a mechanism for disseminating non-routing information throughout an OSPF domain using sparse topologies. Discussion centered on manageability and configuration complexity compared to simply putting information in the base instance.
Prefix Unreachability: Debate continued regarding the prefix unreachable draft, specifically the use of the maximum metric (LS Infinity) versus explicit signaling. A major concern was backward compatibility and the impact on existing deployments. There was also a discussion of the informational versus standard track status, given normative language regarding ABR behavior.
Loop Detection: The presentation of a draft addressing loop detection raised significant concerns from the WG. The consensus was that the proposal was too complex, addressed a niche case, and encouraged bad network design practices.
Flowspec Distribution: The draft proposing extensions to OSPF and ISIS for flowspec distribution met with resistance. The working group generally agreed this was not a good use for IGPs and the potential for large LSAs was concerning.

Decisions and Action Items

Prefix Unreachability: The group will discuss whether to pursue an informational or standards track status for the draft, and whether experimental would be better.
Adoption Calls: The WG chair reminded the group about several outstanding adoption call requests from previous interim meetings.
Multi-Part TLV Interim: The group will schedule an interim meeting to discuss multi-part TLV solutions.

Next Steps

Authors of drafts presented should address the comments received during the meeting.
The WG chairs will schedule adoption calls as needed.
The list will be used to further discuss the status of the Prefix Unreachability draft
An interim meeting on Multi-Part TLV will be scheduled.