48-30
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 48 Configuring IP Multicast Routing
Configuring IP Multicast Routing
Switch(config)# access-list 20 deny 239.0.0.0 0.0.255.255
Switch(config)# access-list 20 permit 224.0.0.0 15.255.255.255
In this example, the mapping agent accepts candidate RP announcements from only two devices,
172.16.5.1 and 172.16.2.1. The mapping agent accepts candidate RP announcements from these two
devices only for multicast groups that fall in the group range of 224.0.0.0 to 239.255.255.255. The
mapping agent does not accept candidate RP announcements from any other devices in the network.
Furthermore, the mapping agent does not accept candidate RP announcements from 172.16.5.1
or 172.16.2.1 if the announcements are for any groups in the 239.0.0.0 through 239.255.255.255 range.
This range is the administratively scoped address range.
Configuring PIMv2 BSR
• Defining the PIM Domain Border, page 48-30 (optional)
• Defining the IP Multicast Boundary, page 48-31 (optional)
• Configuring Candidate BSRs, page 48-32 (optional)
• Configuring Candidate RPs, page 48-33 (optional)
For overview information, see the “Bootstrap Router” section on page 48-7.

Defining the PIM Domain Border

As IP multicast becomes more widespread, the chance of one PIMv2 domain bordering another PIMv2
domain is increasing. Because these two domains probably do not share the same set of RPs, BSR,
candidate RPs, and candidate BSRs, you need to constrain PIMv2 BSR messages from flowing into or
out of the domain. Allowing these messages to leak across the domain borders could adversely affect the
normal BSR election mechanism and elect a single BSR across all bordering domains and co-mingle
candidate RP advertisements, resulting in the election of RPs in the wrong domain.
Beginning in privileged EXEC mode, follow these steps to define the PIM domain border. This
procedure is optional.
To remove the PIM border, use the no ip pim bsr-border interface configuration command.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 interface interface-id Specify the interface to be configured, and enter interface configuration
mode.
Step 3 ip pim bsr-border Define a PIM bootstrap message boundary for the PIM domain.
Enter this command on each interface that connects to other bordering
PIM domains. This command instructs the switch to neither send or
receive PIMv2 BSR messages on this interface as shown in Figure 48-5.
Step 4 end Return to privileged EXEC mode.
Step 5 show running-config Verify your entries.
Step 6 copy running-config startup-config (Optional) Save your entries in the configuration file.