Configuring IP Multicast Protocols
December 2005 © Foundry Networks, Inc. 19 - 61
The override parameter directs the Layer 3 Switch to ignore the information learned by a BSR if there is a conflict
between the RP configured in this command and the information that is learned by the BSR. In previous releases,
static RP configuration precedes the RP address learned from the PIM Bootstrap protocol. With this
enhancement, an RP address learned dynamically from PIM Bootstrap protocol takes precedence over static RP
configuration unless the override parameter is used.
You can use the show ip pim rp-set command to display the ACLs used to filter the static RP groups. For
example,
In the example above, the display shows the following information:
• The Group Address table shows the static RP address that is covered by the access list, and whether or not
the override parameter has been enabled.
• The Group prefix line shows the multicast group prefix for the static RP.
• The RP # line shows the configured IP address of the RP candidate.
The show ip pim rp-map to show the group-to-RP mapping.
The display shows the multicast group addresses covered by the RP candidate and the IP address of the RP for
the listed multicast group. In the example above, you see the following:
• The first three lines show the multicast group addresses that are covered by the RP candidate.
• The last three lines show the multicast group addresses covered by the static RP.
Using ACLs to Limit PIM RP Candidate Advertisement
You can use standard ACLs to control the groups for which the candidate RP will send advertisement messages to
the bootstrap router. For example, ACL 5 can be configured to be applied to the multicast groups within the IP
address 239.x.x.x range. You can configure the Layer 3 Switch to advertise itself as a candidate RP to the
bootstrap router only for groups in the range of 239.x.x.x. Enter commands such as the following:
FastIron SuperX Router(config)# interface ethernet 1/1
FastIron SuperX Router(config-if-1/1)# ip address 99.99.99.5 255.255.255.0
FastIron SuperX Router(config) #show ip pim rp-set
Group address Static-RP-address Override
---------------------------------------------------
Access-List 44 99.99.99.5 On
Number of group prefixes Learnt from BSR: 1
Group prefix = 224.0.0.0/4 # RPs: 1
RP 1: 43.43.43.1 priority=0 age=0
FastIron SuperX Router(config)# show ip pim rp-map
Number of group-to-RP mappings: 6
Group address RP address
-------------------------------
1 239.255.163.1 43.43.43.1
2 239.255.163.2 43.43.43.1
3 239.255.163.3 43.43.43.1
4 239.255.162.1 99.99.99.5
5 239.255.162.2 99.99.99.5
6 239.255.162.3 99.99.99.5