Cisco Systems 78-11741-02 manual Using ODR with Dialer Mappings, IPC-198

Configuring On-Demand Routing

	Command	Purpose
Step 1
	Router(config)# cdp timer seconds	Changes the rate at which CDP updates are sent.
Step 2
	Router(config)# router odr	Enables ODR.
Step 3
	Router(config-router)# timers basic update invalid	Changes the rate at which ODR routes are expired
	holddown flush [sleeptime]	from the routing table.

Other CDP features are described in the Cisco IOS Configuration Fundamentals Configuration Guide, in the “Monitoring the Router and Network” chapter.

Using ODR with Dialer Mappings

For interfaces that specify dialer mappings, CDP packets will make use of dialer map configuration statements that pertain to the IP protocol. Because CDP packets are always broadcast packets, these dialer map statements must handle broadcast packets, typically through use of the dialer map broadcast keyword. The dialer string interface configuration command may also be used.

On DDR interfaces, certain kinds of packets can be classified as interesting. These interesting packets can cause a DDR connection to be made or cause the idle timer of a DDR interface to be reset. For the purposes of DDR classification, CDP packets are considered uninteresting. This classification occurs even while CDP is making use of dialer map statements for IP, where IP packets are classified as interesting.

Cisco IOS IP Configuration Guide

IPC-198