Re: mcast tshoot tips?

I find this a helpful link:

http://blog.ine.com/2010/09/17/troubleshooting-multicast-routing/?utm_sourc
e=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ine+%28INE+CCIE+Blog%29

On 5/1/11 9:17 PM, "ALL From_NJ" <all.from.nj_at_gmail.com> wrote:

>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
>
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Received on Sun May 01 2011 - 21:58:09 ART