BGP MVPN RFC6513, Section 10

Jason Iannone jason.iannone at gmail.com
Tue Feb 23 15:39:19 UTC 2016


Hi all,

I'm having trouble interpreting under what circumstance section 10 of
BGP MVPN comes into play.

The way I read this section, upon the receipt of PIM/IGMP Join to
(*,G) the Receiver Site PE does not signal Type 6 or Type 7 Joins
until a Type 5 Source Active route is received from a Sender Site PE.

If Section 10 assumes the use of ASM groups in the VPN, why develop a
Type 6 Shared Tree Join A-D route for unknown sources?

What are the practical minimum Juniper configurations to support
Section 10 for ASM and (*,G) PIM Join when the PE doesn't know a
source?

CE1---PE1,C-RP-----P-----PE2---CE2
Sender Site-------------------Receiver Site

1. CE1 has no active source
2. CE2 forwards PIM Join (*,G) to PE2 toward PE1,C-RP
3. PE2 eats PIM Join, maintains (*,G) state
4. CE1 generates Register messages to PE1
5. PE1 originates Type 5 (S,G)
6. PE2 receives Type 5 (S,G)
7. PE2 verifies existing (*,G) state
8. PE2 advertises Type 7 Join (S,G)
9. PE2 does PMSI and P-Tunnel attachment
10. PE1 receives (S,G) from PE2
11. PE1 adds PMSI to downstream interfaces
12. Multicast flow end to end
13. Achievement unlocked!

I'm least sure about steps 2 & 3.

Comprehension challenged,

Jason


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