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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter24 Configuring IP Multicast Routing
Configuring IP Multicast Routing
To remove a filter on incoming RP announcement messages, use the no ip pim rp-announce-filter
rp-list access-list-number group-list access-list-number global configuration command.
This example shows a sample configuration on an Auto-RP mapp in g age nt t hat is us ed t o pre ve nt
candidate RP announcements from being accepted from unauthorized candidate RPs:
Switch(config)# ip pim rp-announce-filter rp-list 10 group-list 20
Switch(config)# access-list 10 permit host 172.16.5.1
Switch(config)# access-list 10 permit host 172.16.2.1
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 ca ndid ate RP an nou nc em ent s f rom the se t wo
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 announcemen ts f rom any ot her de vic es i n the net work .
Furthermore, the mapping agent does not accept candidate RP anno unc em ent s f rom 1 72. 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 ra nge.
This range is the administratively scoped address range.
Configuring PIMv2 BSR
BSR automates the distribution of group-to-RP mappings to all routers and multilayer switches in a
PIMv2 network. It eliminates the need to manually configure RP information in every device in the
network. However, instead of using IP multicast to distribute group-to-RP mapping information, BSR
uses hop-by-hop flooding of special BSR messages to distribute the mapping i nformation. For overview
information, see the “Bootstrap Router” section on page 24-8.
This section describes how to set up BSR in your PIMv2 network. I t c onta ins th is conf igur ati on
information:
•Defining the PIM Domain Border, page 24-22
•Defining the IP Multicast Boundary, page 24-24
•Configuring Candidate BSRs, page 24-25
•Configuring Candidate RPs, page 24-26

Defining the PIM Domain Border

As IP multicast becomes more widespread, the chances of one PIMv2 domain bordering another PIMv2
domain is increasing. Because these two domains probably do no t share the sam e se t of R Ps, BSR,
candidate RPs, and candidate BSRs, you need to constrain PIM v2 BSR me ssage s f rom f low ing int o o r
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 a cr oss al l b ord er ing dom ains a nd co-m in gle
candidate RP advertisements, resulting in the election of RPs i n t he w r ong do ma in.
Step5 show running-config Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose