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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 24 Configuring IP Multicast Routing
Configuring IP Multicast Routing
Defining the IP Multicast Boundary
You define a multicast boundary to prevent Auto-RP messages from entering the PIM domain. You
create an access list to deny packets destined for 224.0.1.39 and 224.0.1.40, which carry Auto-RP
information.
Beginning in privileged EXEC mode, follow these steps to define a multicast boundary:
To remove the boundary, use the no ip multicast boundary interface configuration command.
This example shows a portion of an IP multicast boundary configuration that denies Auto-RP
information:
Switch(config)# access-list 1 deny 224.0.1.39
Switch(config)# access-list 1 deny 224.0.1.40
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# ip multicast boundary 1
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
access-list access-list-number deny
source [source-wildcard]
Create a standard access list, repeating the command as many times as
necessary.
•
For access-list-number, the range is 1 to 99.
•
The deny keyword denies access if the conditions are matched.
•
For source, enter multicast addresses 224.0.1.39 and 224.0.1.40,
which carry Auto-RP information.
•
(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.
Step 3
interface interface-id
Enter interface configuration mode, and specify the interface to be
configured.
Step 4
ip multicast boundary
access-list-number
Configure the boundary, specifying the access list you created in Step 2.
Step 5
end
Return to privileged EXEC mode.
Step 6
show running-config
Verify your entries.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.
