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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
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Chapter 40 Configuring IP Multicast Routing Configuring Advanced PIM Features

Monitoring the RP Mapping Information

To monitor the RP mapping information, use these commands in privileged EXEC mode:
show ip pim bsr displays information about the elected BSR.
show ip pim rp-hash group displays the RP that was selected for the specified group.
show ip pim rp [group-name | group-address | mapping] displays how the switch learns of the RP
(through the BSR or the Auto-RP mechanism).

Troubleshooting PIMv1 and PIMv2 Interoperability Problems

When debugging interoperability problems between PIMv1 and PIMv2, check these in the order shown:
1. Verify RP mapping with the show ip pim rp-hash privileged EXEC command, making sure that all
systems agree on the same RP for the same group.
2. Verify interoperability between different versions of DRs and RPs. Make sure the RPs are
interacting with the DRs properly (by responding with register-stops and forwarding decapsulated
data packets from registers).
Configuring Advanced PIM Features
These sections describe the optional advanced PIM features:
Understanding PIM Shared Tree and Source Tree, page 40-33
Delaying the Use of PIM Shortest-Path Tree, page 40-35 (optional)
Modifying the PIM Router-Query Message Interval, page 40-36 (optional)

Understanding PIM Shared Tree and Source Tree

By default, members of a group receive data from senders to the group across a single data-distribution
tree rooted at the RP. Figure 40-5 shows this type of shared-distribution tree. Data from senders is
delivered to the RP for distribution to group members joined to the shared tree.