All things related to multicast

[Greg Shepherd <>]

Philip,

mroute state timers for PIM are 3 minutes. This looks like a state timing
war somewhere in the path. Where/when can I call you to help out?

Greg

On Thu, 8 Jun 2000, Philip Pishioneri wrote:

> [I'm resending this because: a copy has never been ACK'd to me, it
> hasn't shown up in the web archives (sent Tuesday), and most
> importantly, there was a typo in the subject ;-]
> 
> I have a problem with our external multicast connection that I'd like to
> run by folks before I get further into debugging it. (Don't know if it's
> related to cef or not.)
> 
> Synopsis: a connection to a group being sourced from outside our domain
> doesn't feed continuously, but starts and stops in a cycle.  It'll
> receive a feed for almost 3 minutes and then it'll stop for almost 4
> minutes, and then repeat.
> 
> Details:  We're starting with an empty slate for multicast.  The
> equipment is various Cisco boxes:
> 
>         - border router: GSR (IOS 12.0(10)S)
>         - internal routers: 8540s (IOS 12.0(5)W5(13b))
>         - switches (55xx's, 29xx's)
> 
> For the campus multicast domain, I'm trying to use just PIM V2 BSR. 
> There's only one BSR candidate and one RP candidate during this initial
> testing, and both are defined on one loopback interface on the GSR
> border router.  CGMP is enabled on the switches.  The internal
> interfaces are running sparse-dense mode.
> 
> The Abilene interface is the MSDP peer, configured according to their
> web site cookbook.
> 
> If I connect to "Places all over the world" (or other announced group),
> I'll receive all of the various sources for almost 3 minutes.  Then,
> they'll all stop for almost 4 minutes.  And it repeats.
> 
> If I have another internal system source a stream into that group, it
> does -not- exhibit this effect, and is received continuously while the
> externals cycle.  (same is true if it is sourcing into a separate
> group.)
> 
> If I have one receiver running, and it's not currently receiving, and I
> start another receiver (on a separate subnet, different router), both
> will start receiving until the latter's ~3 minute time is up, and then
> they're synced to the same cycle.
> 
> I've read about the 3 minute PIM-SM interface timer, and figure that
> this is expiring and causing interfaces to be pruned.  But since the
> internal source keeps working, the (S,G) tree appears to be OK
> internally, and the problem might be at the border.  I'm not certain how
> the ~4 minute quiet time fits into this.
> 
> -Phil
> Cornell University
> 
>