Controlling Route Exchanges; Limiting The Number Of Dvmrp Routes Advertised; Changing The Dvmrp Route Threshold - Cisco Catalyst 3750 Software Configuration Manual

Chapter 31 Configuring IP Multicast Routing

Controlling Route Exchanges

These sections describe how to tune the Cisco device advertisements of DVMRP routes:
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Limiting the Number of DVMRP Routes Advertised

By default, only 7000 DVMRP routes are advertised over an interface enabled to run DVMRP (that is,
a DVMRP tunnel, an interface where a DVMRP neighbor has been discovered, or an interface configured
to run the ip dvmrp unicast-routing interface configuration command).
Beginning in privileged EXEC mode, follow these steps to change the DVMRP route limit. This
procedure is optional.
Command
Step 1
configure terminal
Step 2 ip dvmrp route-limit count
Step 3 end
Step 4
show running-config
Step 5
copy running-config startup-config
To configure no route limit, use the no ip dvmrp route-limit global configuration command.

Changing the DVMRP Route Threshold

By default, 10,000 DVMRP routes can be received per interface within a 1-minute interval. When that
rate is exceeded, a syslog message is issued, warning that there might be a route surge occurring. The
warning is typically used to quickly detect when devices have been misconfigured to inject a large
number of routes into the MBONE.
Beginning in privileged EXEC mode, follow these steps to change the threshold number of routes that
trigger the warning. This procedure is optional.
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Limiting the Number of DVMRP Routes Advertised, page 31-45
Changing the DVMRP Route Threshold, page 31-45
Configuring a DVMRP Summary Address, page 31-46
Disabling DVMRP Autosummarization, page 31-48
Adding a Metric Offset to the DVMRP Route, page 31-48
Configuring Advanced DVMRP Interoperability Features
(optional)
Purpose
Enter global configuration mode.
Change the number of DVMRP routes advertised over an interface
enabled for DVMRP.
This command prevents misconfigured ip dvmrp metric interface
configuration commands from causing massive route injection into the
MBONE.
By default, 7000 routes are advertised. The range is 0 to 4294967295.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3750 Metro Switch Software Configuration Guide
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31-45