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Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 44 Configuring IP Multicast Routing
Configuring Basic DVMRP Interoperability Features
To disable the filter, use the no ip dvmrp accept-filter access-list-number [distance] neighbor-list
access-list-number interface configuration command.
This example shows how to configure a DVMRP tunnel. In this configuration, the IP address of the
tunnel on the Cisco switch is assigned unnumbered, which causes the tunnel to appear to have the same
IP address as port 1. The tunnel endpoint source address is 172.16.2.1, and the tunnel endpoint address
of the remote DVMRP router to which the tunnel is connected is 192.168.1.10. Any packets sent through
the tunnel are encapsulated in an outer IP header. The Cisco switch is configured to accept incoming
DVMRP reports with a distance of 100 from 198.92.37.0 through 198.92.37.255.
Switch(config)# ip multicast-routing
Switch(config)# interface tunnel 0
Switch(config-if)# ip unnumbered gigabitethernet0/1
Switch(config-if)# ip pim dense-mode
Switch(config-if)# tunnel source gigabitethernet0/1
Switch(config-if)# tunnel destination 192.168.1.10
Switch(config-if)# tunnel mode dvmrp
Switch(config-if)# ip dvmrp accept-filter 1 100
Switch(config-if)# interface gigabitethernet0/1
Switch(config-if)# ip address 172.16.2.1 255.255.255.0
Switch(config-if)# ip pim dense-mode
Switch(config)# exit
Switch(config)# access-list 1 permit 198.92.37.0 0.0.0.255
Advertising Network 0.0.0.0 to DVMRP Neighbors
If your switch is a neighbor of an mrouted Version 3.6 device, you can configure the software to
advertise network 0.0.0.0 (the default route) to the DVMRP neighbor. The DVMRP default route
computes the RPF information for any multicast sources that do not match a more specific route.
Do not advertise the DVMRP default into the MBONE.
Step 9 ip dvmrp accept-filter
access-list-number [distance]
neighbor-list access-list-number
Configure an acceptance filter for incoming DVMRP reports.
By default, all destination reports are accepted with a distance of 0.
Reports from all neighbors are accepted.
• For access-list-number, specify the access list number created in
Step 2. Any sources that match the access list are stored in the
DVMRP routing table with distance.
• (Optional) For distance, enter the administrative distance to the
destination. By default, the administrative distance for DVMRP
routes is 0 and take precedence over unicast routing table routes. If
you have two paths to a source, one through unicast routing (using
PIM as the multicast routing protocol) and another using DVMRP,
and if you want to use the PIM path, increase the administrative
distance for DVMRP routes. The range is 1 to 255.
• For neighbor-list access-list-number, enter the number of the
neighbor list created in Step 2. DVMRP reports are accepted only by
those neighbors on the list.
Step 10 end Return to privileged EXEC mode.
Step 11 show running-config Verify your entries.
Step 12 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose