Ed, Your routers downstream that are not directly connected will not ever get the RP mappings from the MA. So when you do "sh ip pim rp map" you won't find anything. Why? Well...everything is running in sparse-mode. What happens in sparse mode? It only gets sent downstream when there is a specific request for it right? Auto-RP works with dense mode.
So the MA sends out the information about the RPs using a multicast to 224.0.1.40 ... It hits the first router in your topology. That router says "hmmmm I am in sparse-mode and nobody has requested 224.0.1.40 so I'm not going to send it on" With ip pim autorp listener it happens like this: MA sends out the information about the RPs using a multicast to 224.0.1.40. It hits the first router that has ip pim autorp listener configured and it now says "OOOOOOOO, 224.0.1.40, I am specifically configured to forward that down the stream just as if I was in dense mode...but ONLY that address." and sends it on down. The other routers do the same. - Joe On Wed, Jul 15, 2009 at 10:17 AM, Bryan Bartik <[email protected]> wrote: > Autorp messages will be received by directly connected routers, but nothing > beyond that. Try a larger scenario where there are more routers in your > topology. If you use sparse-dense mode, then of course autorp listener is > not needed. > > > On Wed, Jul 15, 2009 at 7:01 AM, Bodnar, Edward > <[email protected]>wrote: > >> So if I was missing the Autorp listner command nothing would work ? >> Every time I think I have the configuration correct. I check the answers >> and they say I need autorp listner. >> >> >> >> >> >> If I added this command and it was not needed do you think I would lose >> points? >> >> >> >> *From:* Bryan Bartik [mailto:[email protected]] >> *Sent:* Wednesday, July 15, 2009 8:58 AM >> *To:* Bodnar, Edward >> *Cc:* [email protected]; CCIE OSL >> *Subject:* Re: Auto RP listner >> >> >> >> Edward, >> >> How do you verify that auto RP is working and propagating RP >> information...show ip pim....? :) >> >> On Wed, Jul 15, 2009 at 5:14 AM, Bodnar, Edward <[email protected]> >> wrote: >> >> OK I need to ask this question one last time but in a different way. >> >> Lets say I am working through Multicast and I forget to put AutoRP listner >> on. What would nto be working and how could I tell that it's not working. >> >> Example. I need Autorp listner but forget to put it on. >> I do sho ? and realize that it's not working and I need to add this >> command. >> >> >> Can anybody help. Cant believe I am still frustrated over this command. >> Everything just seems to work with it on or without it. >> >> >> >> >> -- >> Bryan Bartik >> CCIE #23707 (R&S), CCNP >> Sr. Support Engineer - IPexpert, Inc. >> URL: http://www.IPexpert.com >> > > > > -- > Bryan Bartik > CCIE #23707 (R&S), CCNP > Sr. Support Engineer - IPexpert, Inc. > URL: http://www.IPexpert.com > -- Regards, Joe Astorino - CCIE #24347 R&S Technical Instructor - IPexpert, Inc. Cell: +1.586.212.6107 Fax: +1.810.454.0130 Mailto: [email protected]
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