Cisco Catalyst 3750 - Responding to Mrinfo Requests; Configuring Advanced DVMRP Interoperability Features

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Catalyst 3750 Metro Switch Software Configuration Guide
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Chapter 31 Configuring IP Multicast Routing
Configuring Advanced DVMRP Interoperability Features
To prevent the default route advertisement, use the no ip dvmrp default-information interface
configuration command.
Responding to mrinfo Requests
The software answers mrinfo requests sent by mrouted systems and Cisco routers and multilayer
switches. The software returns information about neighbors through DVMRP tunnels and all the routed
ports. This information includes the metric (always set to 1), the configured TTL threshold, the status of
the port, and various flags. You can also use the mrinfo privileged EXEC command to query the router
or switch itself, as in this example:
Switch# mrinfo
171.69.214.27 (mm1-7kd.cisco.com) [version cisco 11.1] [flags: PMS]:
171.69.214.27 -> 171.69.214.26 (mm1-r7kb.cisco.com) [1/0/pim/querier]
171.69.214.27 -> 171.69.214.25 (mm1-45a.cisco.com) [1/0/pim/querier]
171.69.214.33 -> 171.69.214.34 (mm1-45c.cisco.com) [1/0/pim]
171.69.214.137 -> 0.0.0.0 [1/0/pim/querier/down/leaf]
171.69.214.203 -> 0.0.0.0 [1/0/pim/querier/down/leaf]
171.69.214.18 -> 171.69.214.20 (mm1-45e.cisco.com) [1/0/pim]
171.69.214.18 -> 171.69.214.19 (mm1-45c.cisco.com) [1/0/pim]
171.69.214.18 -> 171.69.214.17 (mm1-45a.cisco.com) [1/0/pim]
Configuring Advanced DVMRP Interoperability Features
Cisco routers and multilayer switches run PIM to forward multicast packets to receivers and receive
multicast packets from senders. It is also possible to propagate DVMRP routes into and through a PIM
cloud. PIM uses this information; however, Cisco routers and multilayer switches do not implement
DVMRP to forward multicast packets.
These sections describe how to perform advanced optional configuration tasks on your switch to
interoperate with DVMRP devices:
• Enabling DVMRP Unicast Routing, page 31-42 (optional)
• Rejecting a DVMRP Nonpruning Neighbor, page 31-43 (optional)
• Controlling Route Exchanges, page 31-45 (optional)
For information on basic DVMRP features, see the “Configuring Basic DVMRP Interoperability
Features” section on page 31-36.
Step 4
end Return to privileged EXEC mode.
Step 5
show running-config Verify your entries.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose