PIM SM RP

Unanswered Question
Feb 3rd, 2009
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Hi,


Can anyone tell me if the RP needs to have the RP address set in a multicast configuration. I can't figure out why my mulitcast won't work, all routers point towards a RP address of 111.111.111.111, but the RP itself does not have the ip pim rp-address 111.111.111.111 configured, I did'nt think it was needed. Question is, is it?


Help rated.


Thanks



Gav

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Harold Ritter Tue, 02/03/2009 - 08:27
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Gav,


You should configure the static RP on the RP itself as well. Also make sure that pim is enabled under the loopback interface if the RP address (111.111.111.111) belongs to that interface.


Regards

gavin.mckee Tue, 02/03/2009 - 09:06
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Hi Thanks for your reply,


I have configued the RP with the rp-address and the loopback with the pim sparse mode commands, however i'm still unable to route the traffic :( . Its quite strange as I have every router configured with the rp address and all the L3 interfaces with pim sparse mode.

gavin.mckee Tue, 02/03/2009 - 09:52
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Here is the debug ip pim from the switch i am trying to source the multicast traffic from


dub-access-sw#

Feb 3 17:46:18: PIM(0): Check RP 111.111.111.111 into the (*, 239.0.1.2) entry Feb 3 17:46:18: PIM(0): Building Triggered (*,G) Join / (S,G,RP-bit) Prune message for 239.0.1.2 Feb 3 17:46:18: PIM(0): Insert (*,239.0.1.2) join in nbr 10.69.224.29's queue Feb 3 17:46:18: PIM(0): Building Join/Prune packet for nbr 10.69.224.29 Feb 3 17:46:18: PIM(0): Adding v2 (111.111.111.111/32, 239.0.1.2), WC-bit, RPT-bit, S-bit Join Feb 3 17:46:18: PIM(0): Send v2 join/prune to 10.69.224.29 (GigabitEthernet1/0/1) dub-access-sw# Feb 3 17:46:29: PIM(0): Received RP-Reachable on GigabitEthernet1/0/1 from 111.111.111.111 Feb 3 17:46:29: PIM(0): Received RP-Reachable on GigabitEthernet1/0/1 from 111.111.111.111

Feb 3 17:46:29: for group 239.0.1.2

dub-access-sw#

Feb 3 17:46:33: PIM(0): Insert (111.111.111.111,239.0.1.2) prune in nbr 10.69.224.29's queue Feb 3 17:46:33: PIM(0): Building Join/Prune packet for nbr 10.69.224.29 Feb 3 17:46:33: PIM(0): Adding v2 (111.111.111.111/32, 239.0.1.2), WC-bit, RPT-bit, S-bit Prune Feb 3 17:46:33: PIM(0): Send v2 join/prune to 10.69.224.29 (GigabitEthernet1/0/1)


Harold Ritter Tue, 02/03/2009 - 13:37
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Gavin,


Here's a couple of step to troubleshoot the issue.


1. You should make sure that the RP address is advertised in your IGP.


2.Check is that the first hop router (router directly connected to the source) is registring with the RP (sh ip mroute "


3. Check that there is active receiver and that they join the shared tree ("sh ip mroute " on the RP.


Regards

Mohamed Sobair Tue, 02/03/2009 - 12:54
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Hi,


Routers part of the Group needs to know their mapping information from the mapping agent.


The mapping agent looks like OSPF "DR" in a segment, any RPs information for a multicast group are forwarded by the mapping agent. Then routers build a shared tree toward the RP, Keep in mind taht "ip pim spt threshhold infinity" has to be configured on the Designated router on a LAN segment "IGMP querier" in order to prevent the router to switch to the shortest path tree.


Also for a router to send pim "register-stop" message toward the source, it has to be the RP.


HTH

Mohamed

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