48-49
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 48 Configuring IP Multicast Routing Configuring Basic DVMRP Interoperability Features
To remove the boundary, use the no ip multicast boundary interface configuration command.
This example shows how to set up a boundary for all administratively-scoped addresses:
Switch(config)# access-list 1 deny 239.0.0.0 0.255.255.255
Switch(config)# access-list 1 permit 224.0.0.0 15.255.255.255
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# ip multicast boundary 1
Configuring Basic DVMRP Interoperability Features
• Configuring DVMRP Interoperability, page 48-49 (optional)
• Configuring a DVMRP Tunnel, page 48-51 (optional)
• Advertising Network 0.0.0.0 to DVMRP Neighbors, page 48-53 (optional)
• Responding to mrinfo Requests, page 48-54 (optional)
For more advanced DVMRP features, see the “Configuring Advanced DVMRP Interoperability
Features” section on page 48-54.

Configuring DVMRP Interoperability

Cisco multicast routers and multilayer switches using PIM can interoperate with non-Cisco multicast
routers that use the DVMRP.
PIM devices dynamically discover DVMRP multicast routers on attached networks by listening to
DVMR probe messages. When a DVMRP neighbor has been discovered, the PIM device periodically
sends DVMRP report messages advertising the unicast sources reachable in the PIM domain. By default,
directly connected subnets and networks are advertised. The device forwards multicast packets that have
been forwarded by DVMRP routers and, in turn, forwards multicast packets to DVMRP routers.
You can configure an access list on the PIM routed interface connected to the MBONE to limit the
number of unicast routes that are advertised in DVMRP route reports. Otherwise, all routes in the unicast
routing table are advertised.
Note The mrouted protocol is a public-domain implementation of DVMRP. You must use mrouted Version 3.8
(which implements a nonpruning version of DVMRP) when Cisco routers and multilayer switches are
directly connected to DVMRP routers or interoperate with DVMRP routers over an MBONE tunnel.
DVMRP advertisements produced by the Cisco IOS software can cause older versions of the mrouted
protocol to corrupt their routing tables and those of their neighbors.
You can configure what sources are advertised and what metrics are used by configuring the ip dvmrp
metric interface configuration command. You can also direct all sources learned through a particular
unicast routing process to be advertised into DVMRP.