All things related to multicast

[John Kristoff <>]

On Wed, 10 Aug 2016 23:59:55 +0300
"Zenon Mousmoulas" 
<>
 wrote:

> What's your problem with MSDP?

It was mostly OK for the little deployment of it we had all those years.
If interdomain IP multicast was widely deployed its problems would
become more apparent.  My last serious IP multicast presentation is
here:

  <https://www.nanog.org/meetings/nanog35/presentations/kristoff.pdf>

Implicit in many of those slides, including the couple on MSDP is the
challenge of ensuring stability, reliability and integrity in the face
of unauthenticated end host-driven network state and processing.

Scaling interdomain IP multicast was an ongoing problem, with MSDP being
one of the more obvious places where problems arose.  I'm willing to bet
much of what is in MSDP is noise and not really intended to be
available outside the source AS.  Rate limiting and filtering will
only get us so far until we would have to effectively turn it off and
do "something else" to keep it going.  It is even hard to know for sure
what the MSDP trends are though, because no one is doing any MSDP
monitoring anymore from what I can tell.  That too is a problem.

> At the current, limited scale of inter-domain multicast, what
> operational issues have you seen with MSDP in the last few years?

I actually only just rejoined a network that even had IP multicast
widely deployed.  So recently no current MSDP issues, and certainly
none expected now.  I'm being proactive. :-)  Just before I left
Northwestern, I think this was the last one I ran into:

  <https://lists.internet2.edu/sympa/arc/wg-multicast/2005-06/msg00000.html>

John