I was playing around with multicast and I've run into a situation I would like your comments :)
I have 4 routers connected like this:
-R3 is a static configured RP.
-all interfaces except R1 are running PIM-SM.
From R1, I'm sending a ping to a multicast address using Loopback0 IP as source and sending it out via the interface to R2 (using an extended ping to be sure the exit interface and source addr).
Making no ip mroute-cache and debugging ip mpacket I see that R2 is giving a RPF check error. I've checked R2 with "show ip rpf R1-Lo0" and it shows the correct interface, also correct exit interface in the routing table and CEF.
If I source the multicast ping using the interface (physical) address then everything works fine.
Can someone give me a hint why I can't source it from the loopback? Shouldn't it be possible?
00:06:46: IP(0): s=10.1.7.7 (FastEthernet0/0) d=188.8.131.52 id=17, ttl=254, prot=1, len=114(100), not RPF interface
R2#sh ip route 10.1.7.7
Routing entry for 10.1.7.7/32
Known via "ospf 1", distance 110, metric 2, type intra area
Last update from 10.1.37.7 on FastEthernet0/0, 00:15:04 ago
Routing Descriptor Blocks:
* 10.1.37.7, from 10.1.7.7, 00:15:04 ago, via FastEthernet0/0
Route metric is 2, traffic share count is 1
R2#sh ip rpf 10.1.7.7
RPF information for ? (10.1.7.7)
RPF interface: FastEthernet0/0
RPF neighbor: ? (10.1.37.7)
RPF route/mask: 10.1.7.7/32
RPF type: unicast (ospf 1)
RPF recursion count: 0
Doing distance-preferred lookups across tables
----- now using interface IP (at the moment nobody joined the group)
00:05:18: IP(0): s=10.1.37.7 (FastEthernet0/0) d=184.108.40.206 id=5, ttl=254, prot=1, len=114(100), mroute olist null