Session Date/Time: 19 Mar 2024 23:30

spring

Summary

The SPRING working group meeting at IETF 119 in Brisbane covered a range of topics related to Segment Routing, including compression, security, micro-segmentation, flexible path selection, circuit-style SR policies, and path verification. Discussions focused on addressing open issues in existing drafts and exploring potential new features and solutions.

Key Discussion Points

Compressed SRv6 Encoding: Discussion centered on the outstanding issue of L4 checksum verification and the role of middle boxes. Agreement was reached to raise awareness of potential issues with middle boxes and leave deployment decisions to operators.
SRv6 Security Considerations: Concerns were raised about the lack of gap analysis and coverage of existing security considerations in RFC 8754. The need to survey existing SRv6 security documents and integrate relevant information was emphasized.
Micro-segmentation: The proposal for a MicroTAP segment for traffic capture was presented. Concerns were raised about potential changes to packet hashing and the origin of the microtap SID and its security implications.
Flexible SR Policy Path Selection: The draft proposes dynamically adjusting SR policy paths based on quality requirements. Concerns were raised about the interaction with BGP-SR and the potential for increased churn in route advertisements.
Circuit-Style SR Policy Optimization: A proposal to optimize seed lists for circuit-style SR policies was presented. Discussions focused on potential issues with FRR and the trade-offs between binding SIDs and operational complexity.
SRv6 Policy Resource Guaranteed Next-Hop Selection: Discussion centered on the practicality of having a large number of per-NRP SIDs and possible alternative approaches using in-packet indications.
Proof of Transit: An approach to proving traffic transit through a set of nodes using asymmetric cryptography was presented. There was discussion about the scope of the problem and potential scalability concerns.
Path Verification for SRv6: A solution based on SRv6 to verify network path was presented, including source and path verifications, privacy protections, and fault localizations.

Decisions and Action Items

Compressed SRv6 Encoding: Update the draft to include awareness of L4 checksum verification issues with middle boxes. Take the discussion back to the list for further refinements.
SRv6 Security Considerations: Take to the mailing list to figure out how to proceed with adoption of the security document. Incorporate survey of existing security considerations, including RFC 8754.
Micro-segmentation: Take the discussion of security concerns related to the origin of MicroTep SID to the mailing list.
SRv6 Policy Resource Guaranteed Next-Hop Selection: Take to the mailing list and consider if it should be combined or merged with other similar working group documents.

Next Steps

Authors to revise drafts based on meeting feedback.
Further discussions to take place on the mailing list for open issues and draft progression.
Consideration of adoption for several drafts (e.g., SRv6 Security Considerations, SRv6 Policy Resource Guaranteed Next-Hop Selection) after addressing open issues.