All things related to multicast

["Marshall Eubanks" <>]

>[I finally fixed my nlanr/AG beacon and went to test it and discovered
>multicast had broken on my subnet:-].
>
>So this time, we have a router that has one of it's two redundant
>links to the rest of the campus routers down (dual star topology;
>subnets 1 and 2).  All campus routers with the exception of the I2
>router (and RP) are on subnets 1 and 2.  The I2 router is only on
>subnet 1.  The router that has a link down has subnet 1 down.  Unicast
>routing works just fine via subnet 2 where one of the other half-dozen
>routers moves the subject router's traffic from subnet 2 back to
>subnet 1 for access to the I2 router/RP.
>
>We are using auto-rp.  I do a "show ip pim rp" successively and see
>the RP present for a very small number of groups, and then a second
>later no RPs, and then a while later RPs but again only for a small
>number of groups.  I have some debug output that I'll send to TAC
>RSN....  
>
>The workaround was to manually configure the I2 router as the RP (ip
>pim rp-address 128.59.0.6) and multicast connectivity is back.
>
>So I guess it's something funky going on with the way auto-rp works which
>I thought was PIM-DM which is why the router interfaces have to be configured

>in sparse-dense mode.
>
>IOS version is: 
>
>IOS (tm) c6sup2_rp Software (c6sup2_rp-JSV-M), Experimental Version 
>12.1(20010728:011232)
[shj-V121_8A_E 109]
>
>It's stable, really!  It was built a whole week ago:-)
>
>/a
>
>PS: This time when Phil at Cornell replies saying how he solved it I
>    will pay attention and not just save the mail for 6 months!
>

There was a recent problem at an ISP I know of where they
upgraded their IOS and auto-rp messages started leaking through
filters (or started being paid attention to) - I have also
heard of similar problems with BSR messages after upgrades.

Did you recently do an IOS change ?

Marshall Eubanks
Multicast Technologies.
>

Marshall Eubanks