[Xorp-users] Questions on multicast routing.

[Ben Greear]

Pavlin Radoslavov wrote:
>>> After that use "show pim rps" to check that all PIM-SM routers have
>>> same Cand-RP set.
>> This is on a different machine, but logically it is the same setup,
>> though the interface names are a bit different.  I think that it's not
>> doing the BSR stuff correctly.  That cli output is at the bottom
>> of the email.  I tried sniffing the link between the two routers, but
>> I don't see anything that is obviously BSR stuff.  Any idea what those
>> packets look like in wireshark?
>>
>> Router-0:
>> root at lanforge-D0-20> show pim rps
>> RP              Type      Pri Holdtime Timeout ActiveGroups GroupPrefix
>> root at lanforge-D0-20>
>>
>> Router-1:
>> root at lanforge-D0-20> show pim rps
>> RP              Type      Pri Holdtime Timeout ActiveGroups GroupPrefix
>> root at lanforge-D0-20>
> 
> Empty Cand-RP set is the reason you don't have multicast routing
> working. Debugging the BSR mechanism can be time consuming and for
> your purpose I don't think it is important. You might want to use a
> static RP which is much easier to configure and understand.
> 
> Anyway, if you really want to debug the BSR issue, use commands like
> "show pim bootstrap" and "show pim bootstrap rps". After the
> Bootstrap router is elected, all Cand RPs will start unicasting
> Cand-RP-Adv messages to it.
> The PIM Bootstrap message is multicast periodically (group 224.0.0.13)
> and propagated hop-by-hop.
> 
> Pavlin

Ok, thanks for that info.  I think I'll spend a few minutes
trying to understand the BSR code a bit to make sure it's not just
some simple problem.  I like the idea of everything just being automated,
since my routers may come and go from the network.

The bootstrap code is in pim/pim_bsr.cc primarily?

Thanks,
Ben

-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com