Cisco Systems OL-6426-02 Benutzerhandbuch

The following three examples show sample configurations for the three dial backup methods.

!

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

PPP over ATM 

PPP over Ethernet

Yes

Backup interfaces

Floating static routes

Dialer watch

Floating static route and dialer watch need a routing protocol 
to run in the router. The dialer watch method brings up the 
backup interface as soon as the primary link goes down. The 
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, 
SNAP, and MUX)

Yes

Backup interfaces

Floating static routes

Dialer watch

If bridging is done through the WAN interface, it is not 
supported across the auxiliary port.