Cisco Catalyst 3550 series Software Configuration Manual page 837

Chapter 34 Configuring IP Multicast Routing
Beginning in privileged EXEC mode, follow these steps to configure a DVMRP tunnel:
Command
Step 1
configure terminal
Step 2
access-list access-list-number {deny |
permit} source [source-wildcard]
Step 3
interface tunnel number
Step 4
tunnel source ip-address
Step 5 tunnel destination ip-address
Step 6 tunnel mode dvmrp
Step 7
ip address address mask
or
ip unnumbered type number
Step 8 ip pim [dense-mode | sparse-mode]
Step 9
ip dvmrp accept-filter
access-list-number [distance]
neighbor-list access-list-number
Step 10
end
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Purpose
Enter global configuration mode.
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.
Enter interface configuration mode, and specify a tunnel interface.
Specify the source address of the tunnel interface. Enter the IP address
of the interface on the multilayer switch.
Specify the destination address of the tunnel interface. Enter the IP
address of the mrouted router.
Configure the encapsulation mode for the tunnel to DVMRP.
Assign an IP address to the interface.
or
Configure the interface as unnumbered.
Configure the PIM mode on the interface.
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.
Return to privileged EXEC mode.
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring Basic DVMRP Interoperability Features
34-47