Cisco Systems OL-6426-02 manual Configuration Example, 13-6

Chapter 13 Configuring Dial Backup and Remote Management

Dial Backup Feature Limitations

Table 13-1 Dial Backup Feature Support and Limitations Summary (continued)

WAN Encapsulation	Dial Backup
Type	Possible?	Dial Backup Method	Limitations
Cisco 1801, Cisco 1802, or Cisco 1803
PPP over ATM	Yes	Backup interfaces	Floating static route and dialer watch need a routing protocol
PPP over Ethernet		Floating static routes	to run in the router. The dialer watch method brings up the
			backup interface as soon as the primary link goes down. The
		Dialer watch
			backup interface is brought down as soon as the dialer
			timeout is reached and the primary interface is up. The router
			checks the primary interface only when the dialer timeout
			expires. The backup interface remains up until the dialer
			timeout is reached, even though the primary interface is up.
			For the dialer watch method, a routing protocol does not need
			to be running in the router, if the IP address of the peer is
			known.
RFC 1483 (AAL5,	Yes	Backup interfaces	If bridging is done through the WAN interface, it is not
SNAP, and MUX)		Floating static routes	supported across the auxiliary port.
		Dialer watch

Configuration Example

		The following three examples show sample configurations for the three dial backup methods.
		Example 13-1 Configuring Dial Backup Using Backup Interfaces
	!
		vpdn enable
	!
		vpdn-group 1
		accept-dialin
		protocol pppoe
	!
		!Specifies the ISDN switch type
		isdn switch-type basic-net3
	!
		interface vlan 1
		ip address 192.168.1.1 255.255.255.0
		hold-queue 100 out
	!
		!ISDN interface to be used as a backup interface
		interface BRI0
		no ip address
		encapsulation ppp
		dialer pool-member 1
		isdn switch-type basic-net3
	!
		interface ATM0
		backup interface BRI0
		no ip address
		no atm ilmi-keepalive
		pvc 1/40
		encapsulation aal5snap
		pppoe-client dial-pool-number 2
		Cisco 1800 Series Integrated Services Routers (Fixed) Software Configuration Guide
13-6		OL-6426-02