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3. Use the show ip mroute group-address command to verify that R104 has the (*,239.1.1.20) and (10.1.1.1, 239.1.1.20) entries while it is
forwarding multicast packets for group 239.1.1.20 sourced from 10.1.1.1, as shown below.
r104# show ip mroute 239.1.1.20
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report
Outgoing interface flags: H - Hardware switched
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.20), 00:07:10/00:00:00, RP 0.0.0.0, flags: DCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Tunnel0, Forward/Sparse-Dense, 00:07:10/00:00:00
Ethernet0/0, Forward/Sparse-Dense, 00:07:10/00:00:00
(10.1.1.1, 239.1.1.20), 00:01:13/00:02:24, flags: CLT
Incoming interface: Tunnel0, RPF nbr 192.168.24.1, Mroute
Outgoing interface list:
Ethernet0/0, Forward/Sparse-Dense, 00:01:13/00:00:00
NOTE: In (10.1.1.1, 239.1.1.20), the incoming interface is Tunnel0 and the RPF neighbor is 192.168.24.1—the Tunnel head end on R102.
The RPF verification is done based on the Mroute configured on R104, and the multicast packets are pushed out to the OIL to the receiver
connected on the Ethernet 0/0 interface.
4. Use the show ip rpf ip-address command to perform an RPF verification for packets sourced from 10.1.1.1. The following example confirms
that RPF for 10.1.1.1 is via Tunnel 0, on which we are receiving the multicast (S,G) packets.
r104> show ip rpf 10.1.1.1
RPF information for ? (10.1.1.1)
RPF interface: Tunnel0
RPF neighbor: ? (192.168.24.1)
RPF route/mask: 10.1.1.1/24
RPF type: static
RPF recursion count: 0
Doing distance-preferred lookups across tables
Certain show commands are supported by the Output Interpreter tool, which allows you to view an analysis of show command output.