
R8#ping 239.5.5.5
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 239.5.5.5, timeout is 2 seconds:
Reply to request 0 from 5.5.5.5, 55 ms
Reply to request 0 from 5.5.5.5, 56 ms
R8#mtrace 10.10.7.8 10.10.1.5 239.5.5.5
Type escape sequence to abort.
Mtrace from 10.10.7.8 to 10.10.1.5 via group 239.5.5.5
From source (?) to destination (?)
Querying full reverse path...
0 10.10.1.5
-1 10.10.4.4 ==> 10.10.3.4 PIM [10.10.7.0/27]
-2 10.10.3.7 ==> 10.10.6.7 PIM [10.10.7.0/27]
-3 10.10.6.2 ==> 10.10.7.2 PIM_MT [10.10.7.0/27]
-4 10.10.7.8 ==> 10.10.7.8 PIM_MT [10.10.7.8/32]
-5 10.10.7.8
Why does R8 select e0/1, not e0/0 ?
Why does R2 select R7, not R3?
RPF
R5#sh ip rpf 10.10.7.8
RPF information for ? (10.10.7.8)
RPF interface: Ethernet0/2
RPF neighbor: ? (10.10.1.4)
RPF route/mask: 10.10.7.0/27
RPF type: unicast (ospf 10)
Doing distance-preferred lookups across tables
RPF topology: ipv4 multicast base, originated from ipv4 unicast base
R5#sh ip route 10.10.7.8
Routing entry for 10.10.7.0/27
Known via "ospf 10", distance 110, metric 40, type intra area
Last update from 10.10.1.4 on Ethernet0/2, 00:15:54 ago
Routing Descriptor Blocks:
* 10.10.1.4, from 8.8.8.8, 00:15:54 ago, via Ethernet0/2
Route metric is 40, traffic share count is 1
I read
http://www.cisco.com/en/US/docs/ios/12_4t/ip_mcast/configuration/guide/mctlsplt.html#wp1061381
Based on the highest PIM neighbor behavior, R5 should select R1 for RPF, right ?
thanks for any comments !!