[j-nsp] MVPN hub-and-spoke issue

Cydon Satyr cydonsatyr at gmail.com
Thu Sep 22 05:40:01 EDT 2016

Hello experts,
I'm struggling with this specific scenario for hub-and-spoke MVPN network I
It is just a regular hub-and-spoke unicast L3VPN with two links that needs
to have multicast now.

                               | |
                               | |
                               | |
             export 1:1                    export 1:1
             import 2:2                    import 2:2

vrf spoke-to-hub R-only site / import 1:1
vrf hub-to-spoke S-only site / import 1:1 export 2:2

Pim-Join  S1-->spoke-to-hub-->H-CE-->hub-to-spoke-->S2
Multicast S2-->hub-to-spoke-->H-CE-->spoke-to-hub-->S1

The issue is that, when spoke S2 advertises PMSI Attribute in Type 1 NLRI
in order to signal proper Tunnel ID for RSVP p2mp, the tunnel actually gets
built to hub vrf hub-to-spoke. When multicast is sent from S2 toward S1
over H, instead terminating on vrf spoke-to-hub (this is where Join was
received from), it terminated on other one (rpf check fails). In other
words, H puts wrong table-label associated with wrong MVPN vrf.

Why is H router answering with label associated with MVPN vrf which is
configured with sender-site option?

My understanding is that both vrfs on hub need to import inet-mvpn routes
sent from spokes - the receiver site because it needs to know Tunnel ID in
BGP message, and sender vrf because it needs to build I-PMSI itself.
Crazy thing is if I don't import routes into this sender vrf site, then H
correctly puts label associated with receiver hub site in RSVP Resv going
to S2??

I will gladly post more info, maybe some of you guys with MVPN experience
already have some idea?

Let me know please


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