mcast tshoot tips?

Hey team,

Was doing some mcast tshooting today, and wanted to get some ideas or links
that you think will be helpful for the lab and tshoot section. I am worried
about the amount of time, and complexity of this ... especially since in the
config section of the lab, this mcast technology will 'sit on top of' the
other technologies I have already configured; IGPs, etc ...

On the RP:
Whenever you add a source or destination, it should show up in the mroute
table. So in this way, you can tshoot either the source or group membership
problems. Which direction has the problem; from the source or from the
join-group? For those who want to lab this, try it since it is a quick lab
test. Add a source or join-group, and then check the RP's table. It is
quite cool to see this show up in the mroute table.

Team question - what is the fastest way to tell if you have a RPF failure?
I can imagine being in the lab and getting confused with topology and
direction of routes.

What is the quickest way to resolve a RPF failure? My thoughts below,
please add to this:

1) Static mroute (How many routers could potentially need these static
mroutes?)
2) Admin distance, cost, etc ... or other tweaks to prefer a path without
removing the routes? Trying to maintain the reachability, which making the
mcast route also the best IGP route ...
3) Any preferred debugs that might tell you what to configure to solve the
RPF failure?

Suggestion for problem resolution: start a long ping process from the
source, and as you are resolving the problem, when you fixed the problem,
the ping will start to work. Is this a good method, anyone else try this?

From Narbik - add loopbacks with the igmp join-group. Do this along the
path, and where the ping stops, there is the problem router. Any additional
suggestions to this? Sounds like a good idea.

Likely potential problems IMO ...

1) PIM or ip multicast-routing not enabled
2) RP not reachable?
3) RPF failure
4) ACL or firewall? Should this also affect the RP not being reached?
Meaning ... can I skip this check if the RP is reachable and the PIM
messaging is working
5) RP not learning sources or join-groups
6) ???

Team - I am worried about the time I have to resolve tshooting; caused by me
or the tshoot section. I look forward to hearing your thoughts on this
matter.

TIA team and please accept my wishes for you to have a great week!!!

-- 
Andrew Lee Lissitz
all.from.nj_at_gmail.com
Blogs and organic groups at http://www.ccie.net