/mcpMessages on the Router This section provides solutions to the common problem of the IP multicast "INVALID_RP_JOIN" error message. Diagnose the Problem - Part 1 This error messages is received on the Rendezvous Point (RP):
00:55:15: %PIM-6-INVALID_RP_JOIN: Received (, 224.1.1.1) Join from 10.1.6.2 for invalid RP 10.1.5.4 00:56:15: %PIM-6-INVALID_RP_JOIN: Received (, 224.1.1.1) Join from 10.1.6.2 for invalid RP 10.1.5.4
The Cisco IOS Software System Error Messages document explains what causes this error: a downstream PIM router sent a join message for the shared tree, which this router does not want to accept. This behavior indicates that this router allows only downstream routers join to a specific RP. It is suspected it is filtering. You need to take a look at the configuration of the router:
interface Ethernet0/0 ip address 10.1.5.4 255.255.255.0 ip pim sparse-dense-mode ! ip pim accept-rp 10.2.2.2 8 ip pim send-rp-announce Ethernet0/0 scope 15 ip pim send-rp-discovery scope 15 ! access-list 8 permit 224.0.0.0 0.255.255.255
What is the accept-rp statement in the configuration supposed to accomplish? In IP Multicast Routing Commands, it states that "to configure a router to accept Joins or Prunes destined for a specified RP and for a specific list of groups, use the ip pim accept-rp global configuration command. To remove that check, use the no form of this command." When you remove the ip pim accept-rp command, the messages disappear. The command that causes the problem was found, but what if you want to keep that command in the configuration? You can permit the wrong RP address. Enter the show ip pim rp mapping command in order to see the correct RP address:
<#root> ip22-75a# show ip pim rp mapping
PIM Group-to-RP Mappings This system is an RP (Auto-RP) This system is an RP-mapping agent
Group(s) 224.0.0.0/4 RP 10.1.5.4 (?), v2v1