**Session Date/Time:** 22 Jul 2025 07:30

# intarea Session

## Summary
The intarea session at IETF 113 in Madrid covered a variety of topics, including tunnel architecture, proxy configuration, IPv6 next hops for IPv4 routes, multicast application port assignment, and cross-layer vulnerabilities related to ICMP errors. Several drafts were presented, with discussions focusing on their potential adoption, required clarifications, and community impact.

## Key Discussion Points

*   **Tunnels in the Internet Architecture:** Discussions revolved around a long-standing draft defining tunnels as links, addressing terminology, and identifying issues in existing RFCs. Questions were raised about the document's current relevance given the evolution of tunneling practices.
*   **PVD Configuration for Proxies:** A draft proposing a JSON format for proxy configuration within provisioning domains (PVDs) was presented.  Key points included handling exceptions in destination matching rules, vendor-specific key expansion, and guidance on proxy load balancing. Concerns were raised on how to apply rules for resolved IP addresses.
*   **IPv6 Next Hops for IPv4 Routes:** A presentation discussed the possibility of configuring IPv4 routes with IPv6 next hops and vice versa.  Feedback focused on ICMP error handling and implementation considerations. There was discussion about making the document informational or standards track.
*   **Multicast Application Port:** The session covered assigning a specific UDP port (49149) for multicast applications. Discussions centered on ensuring compatibility with existing systems, clarifying the requirements for compliant hosts, and refining IANA considerations.
*   **Cross-Layer Vulnerabilities Due to Forged ICMP Errors:**  A presentation outlined four classes of vulnerabilities arising from forged ICMP errors, including information leakage, shared variable ambiguity, semantic gaps, and identity deception. Proposed solutions included enhanced data validation and stronger lower-layer infrastructure security.  A related presentation proposed a challenge-response mechanism to verify the authenticity of ICMP error messages. Discussion involved the assumption of a single route between hosts for the challenge mechanism to work.
*   **ICMP Error Handling in SRv6 Networks:** A draft on proper ICMP error reporting within SRv6 networks utilizing the uniform model was discussed. The focus was on how ICMP errors triggered within the SRv6 core should be delivered to the client edge (CE) devices.

## Decisions and Action Items

*   **Tunnels in the Internet Architecture:** Hold further discussion on the mailing list.
*   **PVD Configuration for Proxies:**  Revise the draft to address the issue of applying IP subnet matching rules on the resolved address, and initiate working group last call. Consider adding text about sticky proxy selection, for connection reuse.
*   **IPv6 Next Hops for IPv4 Routes:** Update the draft to include guidance on ICMP error handling, and address Jilin’s feedback regarding local-only backbone. Aim for standards track.
*   **Multicast Application Port:** Update the draft based on feedback: add text about existing hosts that may be using the port, clarify error handling, separate the IANA considerations section, and address David's comments about source port usage.
*   **Enhancing SMT error message or syndication:** Revise the draft including that this mechanism might not be supportive.

## Next Steps

*   Authors to revise drafts based on meeting feedback.
*   Further discussions on the mailing lists for drafts not immediately proceeding to last call.
*   Schedule a session request for IETF 124 to discuss traffic needed to have people review and comment drafts and support the work to be moved up.