Re: PIM Convergence Problem

Hmm,
I may be way off, because it is ages since I played with mcast last
time, but PIM does not run on top of the IGP/BGP session, it runs along
and uses the RIB for RPF. If you have pim enabled in the interfaces and
you tear down the BGP session, PIM does not care. After all, it is
independent of the routing protocol, isn't it ?

-Carlos

John Neiberger @ 20/04/2013 13:49 -0300 dixit:
> I posted this on cisco-nsp yesterday and didn't get any replies, so I
> thought I'd run this past the group here.
>
> We ran into an interesting problem last night and I'm a little stumped. It
> appears that PIM did not follow a unicast routing change after a BGP peer
> was shutdown. Imagine this simple topology:
>
> [A] ----- [B] ------ [C] ------- [D]
> |
> |
> |
> [D]
>
> Router A is a CRS and is forwarding PIM joins toward Router D, which is
> directly attached. We are not running an IGP here. There is only an eBGP
> session between two ASes that we manage. We shutdown the BGP session
> between A and D, which caused unicast traffic to switch to the path toward
> Router B. However, it looks like Router A did not tear down the PIM joins
> that are now no longer valid. It seems that it was still joining a lot of
> traffic that it could no longer do anything with since it would now fail
> RPF checks.

Rakesh M @ 21/04/2013 08:10 -0300 dixit:
> Hi,
>
> We had a similar issue with Juniper if my memory goes right. It wont
> refresh until we manually give a clear command. Did you try clearing Pim ?
> Would everything get restored if you bring back the link between A and D ?
>

-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
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