Subject: Re: packet loss between mbone2.UU.Net & SanFrancisco.mci.net

From: "Jeffrey S. Curtis" <[email-masked]>
Date: Mon, 17 Feb 1997 14:39:10 -0600

John McGowan writes:
}Dear Dorian R. Kim,
}
}     Are you able to run successfully with PIM *sparse* mode as well as
}dense mode at your site?  If so, were there any startup problems, odd
}quirks?

I'm not Dorian, but for over a year, I've been running sparse-mode
PIM across my site (and across a T1 to a remote site) with a DMVRP
tunnel to an mrouted machine.  It all works fine now; about 15 of
the mrouters are ciscos running 10.2(x) where x is typically between
11 and 15.  The PIM/DVMRP border router is a cisco running 11.0(13)
which seemed to have a memory leak for a while (it steadily lost
100kB/day for two weeks) but that cleared up coincident with the
end of the most recent Mbone unicast routing screw-up.  It probably
wasn't a memory leak at all.

When I first set this up, I needed to run dense-mode in one part of
the network (including where the PIM cloud touched the DMVRP tunnel),
and that led to some serious memory leaks (several MB/day as I recall),
but this was way back around 10.2(7) or so and I believe it was fixed
by about 10.2(7.3).

One other side note - everywhere where I can use multicast fastswitching,
I *don't*.  I've talked to far too many people who've pulled out far
too much hair troubleshooting what turned out to be fastswitching bugs.
cisco tells me that it's considered safe to use at this point, but since
my traffic is light enough that I have spare cycles right now, I'd rather
burn the CPU than worry about whether the traffic is going to get through.

Jeff
-- 
Jeffrey S. Curtis                      | Internetwork Manager
Argonne National Laboratory            | Email: [email-masked]
9700 South Cass Avenue, ECT-221        | Voice: 630/252-1789
Argonne, IL 60439                      | Fax:   630/252-9689

---

From: Petri Helenius <[email-masked]>
Date: Tue, 18 Feb 1997 16:18:51 +0200 (EET)

> burn the CPU than worry about whether the traffic is going to get through.
They just fixed fastswitching bugs in 11.1(8.1) ... or at least that's
the latest I know of. So I would say that if it works for you fine, if
it doesn't and you have the CPU to spend, go ahead and disable it.

Pete