All things related to multicast

["Marshall Eubanks" <>]

On Wed, 4 Sep 2002 11:13:00 -0500
 Tim Ward 
<>
 wrote:
> Quoting Peter John Hill 
> ():
> > Totally been there and done that. We just got everything stable a few 
> > weeks ago. Give me a call if you want to discuss it
> ...
> > We are using auto-rp with anycast and sparse mode. It is #10 as 
> > described in:
> > http://www.cisco.com/warp/public/cc/pd/iosw/tech/rppim_rg.htm
> 
> When we were rolling out multicast to all of our dorms for our dorm
> TV system, we were seeing odd 60 second dropouts.  We had at the time
> Auto-RP and PIM Sparse.  The scoop from the TAC on the problem is that
> Auto-RP relied on PIM Dense for the auto-RP to work, and that you had
> to configure for PIM Sparse Dense mode if you were using auto-rp. 

That is correct - autorp needs sparse-dense.

The "60" second dropouts are pretty ubiquitous, even if you do auto-rp right.
(In fact, did they go away ?)

The classic case I know of is due to CPU load going > 90% when BGP or
PIM is reconverged every 65 seconds or so, causing forwarding problems. 
There may be other causes.

I spoke about this at the IETF a while ago :
http://www.multicasttech.com/papers/ietf-52-mboned-tme-1.{ps,pdf,ppt}.gz

Marshall
 
> (the heavily distilled version).
> 
> Does this jive with everyone else's experience?
> 
> We were halfway to PIM-Sparse BSR and migrating to anycast rp so I
> didn't think much of it at the time.  But looking at the comments above
> made me wonder.
>