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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 the PIM device configured as the candidate RP, use the no ip pim send-rp-announce global
configuration command. To remove the multilayer switch as the RP-mapping agent, use the no ip pim
send-rp-discovery global configura tion co mman d.
This example shows how to send RP announcements out all PIM-e na bled inte rf aces fo r a maxi mum
of 31 hops. The IP address of Gigabit Ethernet interface 0/1 is the RP. Access list 5 describes the group
for which this multilayer switch serves as RP:
Switch(config)# ip pim send-rp-announce gigabitethernet0/1 scope 31 group-list 5
Switch(config)# access-list 5 permit 224.0.0.0 15.255.255.255
Preventing Join Messages to False RPs
Determine whether the ip pim accept-rp command was previously configured throughout the network
by using the show running-config privileged EXEC command. If the ip pim accept-rp command is not
configured on any device, this problem can be addressed later. In those routers or multilayer switches
already configured with the ip pim accept-rp command, you must enter the command again to accept
the newly advertised RP.
To accept all RPs advertised with Auto-RP and reject all other RPs by default, use the ip pim accept-rp
auto-rp global configuration command.
Step4 access-list access-list-number {deny |
permit} source [source-wildcard]Create a standard access list, repeating the command as many times as
necessary.
•For access-list-number, enter the access list number specified in Step
3.
•The deny keyword denies access if the conditions are matched. The
permit keyword permits access if the conditions are matched.
•For source, enter the multicast group address range for which the RP
should be used.
•(Optional) For source-wildcard, enter the wildcard bits in dotted
decimal notation to be applied to the source. Place ones in the bit
positions that you want to ignore.
Recall that the access list is always terminated by an implicit deny
statement for everything.
Step5 ip pim send-rp-discovery scope ttl Find a multilayer switch whose connectivity is not likely to be
interrupted, and assign it the role of RP-mapping agent.
For scope ttl, specify the time-to-live value in hops to limit the RP
discovery packets. All devices within the hop count from the source
device receive the Auto-RP discovery messages. These messages tell
other devices which group-to-RP mapping to use to avoid confli cts (such
as overlapping group-to-RP ranges). There is no default setting. T he
range is 1 to 255.
Step6 end Return to privileged EXEC mode.
Step7 show running-config Verify your entries.
Step8 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose