MVPN/MSDP SA Interoperation draft-zzhang-bess-mvpn-msdp-sa-interoperation Zhaohui Zhang Lenny Giuliano Juniper Networks IETF 100 BESS WG

MSDP Source Active FHR RP1 discover ASM sources via PIM register mechanism in its local domain and distribute (s,g, rp1) information via SA message to other RPs PIM (*,g) joins terminate at one of the RPs RP6 learns (s,g) via the SA and sends PIM (s,g) join towards the FHR MSDP sessions must be continuous among all RPs RP1 (s,g) register RP2 RP3 (s,g) join RP4 RP5 RP6 LHR (*,g) join MSDP session MSDP (s,g, rp1) SA PIM join IETF 100 BESS WG

MVPN Source Active Inter-site source-tree-only mode C-RP discovers ASM sources via PIM register mechanism and distribute (s,g,c-rp) information via MSDP SA message to its MSDP peers PE1 PE1 advertise MVPN (s,g) SA routes to all PEs Note there is no RP information All PEs learns (s,g) via the SA and PE3 sends (s,g) C-multicast route towards its UMH PE2 PE3 gets (*,g) join from CE but does not send (*,g) C-multicast route PEs are just like RPs in the previous slide, and MVPN/MSDP SAs are similar – except one caveat FHR C-RP (s,g) register PE1 PE2 PE3 PE4 (*,g) join CE LHR (*,g) join MSDP session MSDP (s,g, rp1) SA PIM join MVPN C-multicast route MVPN (s,g) SA IETF 100 BESS WG

MVPN + MSDP A PE does NOT advertise MSDP SAs when it receives MVPN SAs! RFC 6513/6514 does not specify the MVPN SA -> MSDP SA conversion C-RP2 will not get MSDP SAs on its MSDP session with PE3 PE3 will not get (*,g) joins (as they stop at C-RP2), and will not send (s,g) C- multicast route There must be an MSDP session between PE1/PE3, or PE1/C-RP2, or C-RP1/PE3, or C-RP1/C-RP2 To ensure MSDP session continuity These are per-customer MSDP sessions These additional MSDP sessions will cause multiple PEs to advertise excessive MVPN SA routes FHR C-RP1 (s,g) register PE1 PE2 PE3 PE4 X MSDP session C-RP2 LHR MSDP (s,g, rp1) SA (*,g) join MVPN (s,g) SA IETF 100 BESS WG

Solution FHR Treat incoming MVPN SAs as MSDP SAs and trigger outgoing MSDP SAs to peers MVPN SA routes additionally carry an "MVPN SA RP-address Extended Community“ To mimic MSDP (S,A,RP) C-RP1 (s,g) register PE1 PE2 PE3 PE4 PIM (s,g join) MSDP session C-RP2 LHR MSDP (s,g, rp1) SA (*,g) join MVPN (s,g,rp1) SA PIM join MVPN C-multicast route IETF 100 BESS WG

Aren’t we “deprecating MSDP”? Ongoing Mboned discussion about deprecating inter-domain ASM Not about deprecating MSDP Recommendation not mandation MSDP is actually widely used for intra- domain as well This document is for real deployment scenarios that need interoperation between MVPN and customer MSDP infrastructure IETF 100 BESS WG

Next Steps Seeking WG comments Seeking WG adoption IETF 100 BESS WG