RFC-22: Client-Originated PIM Register for Multicast Source Origination#3951
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ben-malbeclabs wants to merge 1 commit into
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RFC-22: Client-Originated PIM Register for Multicast Source Origination#3951ben-malbeclabs wants to merge 1 commit into
ben-malbeclabs wants to merge 1 commit into
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Proposes a client-side PIM Register beacon so the device (anycast RP) originates the MSDP SA for published sources on dual-role publisher/subscriber tunnels, where pim border-router source injection is suppressed by the subscriber-side PIM neighbor. The device change is an additive ACL permit; border-router is retained as a backstop. Builds on RFC-15. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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This seems like a good plan to me. I'm sure it will evolve as implementation happens, but lets merge it, and it can evolve through PRs.
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Summary
Adds RFC-22: Client-Originated PIM Register for Multicast Source Origination (Status: Draft).
When a client both publishes and subscribes to the same multicast group over one GRE tunnel (the simultaneous pub/sub case from RFC-15), the subscriber-side PIM neighbor causes the source's RPF to resolve via that neighbor, which suppresses the device's
pim border-routersource injection. The device never sets theNflag, never originates the MSDP SA, and the source is invisible to the rest of the anycast-RP mesh — so remote subscribers receive it only intermittently (observed on group 233.84.178.5).This RFC proposes that
doublezerodoriginate a PIM Register beacon for its published sources, sent periodically to the RP. Receiving the Register makes the device originate the MSDP SA regardless of border-router suppression — Arista's own lab confirmed that permitting the Register in flips theNflag on. The device-side change is a single additive ACL permit;pim border-routeris retained as a backstop (belt-and-suspenders).Highlights
RegisterSenderreuses the existing heartbeat as the encapsulated packet; beacon semantics (no inbound Register-Stop path).10.0.0.0route is installed in the validator's routing table.Full design, the packet-encapsulation breakdown, alternatives, security, and open questions are in the RFC.
Draft for review. RFC number
22is provisional pending assignment.🤖 Generated with Claude Code