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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 48 Configuring IP Multicast Routing
Configuring Optional Multicast Routing Features
Figure 48-7 Administratively-Scoped Boundaries
You can define an administratively-scoped boundary on a routed interface for multicast group addresses.
A standard access list defines the range of addresses affected. When a boundary is defined, no multicast
data packets are allowed to flow across the boundary from either direction. The boundary allows the
same multicast group address to be reused in different administrative domains.
The IANA has designated the multicast address range 239.0.0.0 to 239.255.255.255 as the
administratively-scoped addresses. This range of addresses can then be reused in domains administered
by different organizations. The addresses would be considered local, not globally unique.
Beginning in privileged EXEC mode, follow these steps to set up an administratively-scoped boundary.
This procedure is optional.
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Company XYZ
Engineering Marketing
239.128.0.0/16
239.0.0.0/8
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 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, the range is 1 to 99.
The deny keyword denies access if the conditions are matched. The
permit keyword permits access if the conditions are matched.
For source, enter the number of the network or host from which the
packet is being sent.
(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 Specify the interface to be configured, and enter interface configuration
mode.
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.