Cisco Systems OL-6426-02 manual Floating Static Routes, Configuring Backup Interfaces, 13-2

Chapter 13 Configuring Dial Backup and Remote Management

Dial Backup Feature Activation Methods

Note Even if the backup interface comes out of standby mode (is brought up), the router does not trigger the backup call unless it receives the specified traffic for that backup interface.

Configuring Backup Interfaces

Perform these steps to configure your router with a backup interface, beginning in global configuration mode:

	Command	Purpose
Step 1
	interface type number	Enters interface configuration mode for the
		interface for which you want to configure backup.
	Example:	This can be a serial interface, ISDN interface, or
	Router(config)# interface atm 0	asynchronous interface.
	Router(config-if)#	The example shows the configuration of a backup
		interface for an ATM WAN connection.
Step 2
	backup interface interface-type	Assigns an interface as the secondary, or backup
	interface-number	interface.
	Example:	This can be a serial interface or asynchronous
		interface. For example, a serial 1 interface could
	Router(config-if)#backup interface bri 0	be configured to back up a serial 0 interface.
	Router(config-if)#	The example shows a Basic Rate Interface
		configured as the backup interface for the ATM 0
		interface.
Step 3
	exit	Enters global configuration mode.
	Example:
	Router(config-if)# exit
	Router(config)#

Floating Static Routes

Floating static routes provide alternative routes for traffic. Floating static routes are not activated unless a DDR backup call has been triggered by specified traffic for a backup interface.

Floating static routes are independent of line protocol status. This is an important consideration for Frame Relay circuits because the line protocol may not go down if the data-link connection identifier (DLCI) is inactive. Floating static routes are also encapsulation independent.

Note When static routes are configured, the primary interface protocol must go down in order to activate the floating static route.

Cisco 1800 Series Integrated Services Routers (Fixed) Software Configuration Guide

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