All things related to multicast

[Stig Venaas <>]

debbie fligor wrote:
> Well, we finally have both on-campus and off-campus multicast routing 
> working without relying on statics (well, we're trying to figure out why 
> we're only receiving some members of group 233.4.200.18 and not others 
> but it's almost all working!).  There's always something bad to go with 
> the good when it comes to multicast it seems....
>
>
> In the process of checking things out across campus to be sure 
> everything was really working correctly now, we found that suddenly our 
> routers that don't allow an "override" command on their static RP config 
> are seeing the following RPs via BSR:
>
> Group prefix = 224.0.0.0/4      # RPs expected: 8
>       # RPs received: 8
>       RP 1: 138.47.14.1    priority=0    age=0
>       RP 2: 130.126.0.145    priority=0    age=0
>       RP 3: 168.223.254.100    priority=0    age=0
>       RP 4: 138.47.102.2    priority=0    age=0
>       RP 5: 199.77.194.253    priority=1    age=0
>       RP 6: 10.10.10.10    priority=1    age=0
>       RP 7: 143.215.194.6    priority=1    age=0
>       RP 8: 89.107.152.145    priority=1    age=0
>
>
> now a year and half ago before everything broke with our new hardware, 
> we don't think that we were seeing these, but that's a long time and a 
> lot of changes beyond us that have happened.  If any of these happen to 
> be your RPs, please consider filtering at your border to help me out :-)
>
> On our exit 6500 (running 12.2(18)SXF9) I added the following (straight 
> from Lab 4 in the IPv4 multicast class) but it doesn't seem to be helping:
>
>
> ip access-list standard multicast-boundary
> deny   224.0.1.39
> deny   224.0.1.40
> permit any

This does not help block BSR, but it is good to block them anyway.
> and then on all router interfaces towards multicast peers did the 
> following:
>
> interface g2/2
> ip pim bsr-border

bsr-border should help. I suggest you try to track down where the
Bootstrap messages (BSMs) come from. Try "show ip pim bsr-router" to see
what the BSR address is, at least I think that will tell you. Once
you know that, try to figure out which interface messages from that
address must come from. You might try "show ip rpf <address>" on your
border routers where <address> is the BSR address. This will show you
which interface the BSMs are received on (there is an RPF check for
receiving BSMs). Hopefully this will help you find some interface you
have forgot to put "ip pim bsr-border" on. Of course it could be that
bsr-border doesn't work for some reason, but that would be news to me
at least.

> ip multicast boundary multicast-boundary
>
>
>
> I don't think I missed any interfaces, I've checked it over a couple of 
> times.  Can anyone think of anything else to suggest or point out that I 
> missed?

Right. Hopefully checking for RPF of the BSR address will help you.

Stig

> -----
> -debbie
> Debbie Fligor, n9dn       Network Engineer, CITES, Univ. of Il
> email: 
>
>           <http://www.uiuc.edu/ph/www/fligor>
>                    "My turn."  -River