Table Of Contents

Configuring Dial Backup with Dialer Profiles

Configure a Dialer Interface

Configure a Physical Interface to Function as Backup

Configure Interfaces to Use a Backup Interface

Dialer Profile for ISDN BRI Backing Up Two Leased Lines Example

Configuring Dial Backup with Dialer Profiles

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Dialer interfaces can be configured as the logical intermediary between one or more physical interfaces and another physical interface that is to function as backup.

Dialer interfaces can be configured to use a specific dialing pool; in turn physical interfaces can be configured to belong to the same dialing pool.

To configure a dialer interface and a specific physical interface to function as backup to other physical interfaces, perform the tasks in the following sections:

•Configure a Dialer Interface

•Configure a Physical Interface to Function as Backup

•Configure Interfaces to Use a Backup Interface

See the "Dialer Profile for ISDN BRI Backing Up Two Leased Lines Example" for a comprehensive backup example using Dialer Profiles. In this example, one BRI functions as backup to two serial lines and can make calls to two different destinations.

For a complete description of the dial backup commands in this chapter, refer to the "Dialer Profiles Backup Commands" chapter of the Dial Solutions Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.

Configure a Dialer Interface

To configure the dialer interface that will be used as an intermediary between a physical interface that will function as backup interface and the interfaces that will use the backup, perform the following tasks beginning in global configuration mode:

Task	Command
Step 1 Create a dialer interface.	interface dialer number
Step 2 Specify IP unnumbered loopback.	ip unnumbered loopback0
Step 3 Specify PPP encapsulation.	encapsulation ppp
Step 4 Specify the remote router's CHAP authentication name.	dialer remote-name name
Step 5 Specify the remote destination to call.	dialer string string
Step 6 Specify the dialing pool to use for calls to this destination.	dialer pool number
Step 7 Assign the dialer interface to a dialer group.	dialer-group number

Configure a Physical Interface to Function as Backup

To configure the physical interface that is to function as backup, perform the following tasks beginning in global configuration mode:

Task	Command
Step 1 Specify the interface.	interface type number
Step 2 Specify PPP encapsulation.	encapsulation ppp
Step 3 Make the interface a member of the dialing pool that the dialer interface will use; make sure the number arguments have the same value.	dialer pool-member number
Step 4 Specify CHAP authentication.	ppp authentication chap

Configure Interfaces to Use a Backup Interface

To configure one or more interfaces to use a backup interface, perform the following tasks beginning in global configuration mode:

Task	Command
Step 1 Specify the interface to be backed up.	interface type number
Step 2 Specify IP unnumbered loopback.	ip unnumbered loopback0
Step 3 Specify the backup interface.	backup interface dialer number
Step 4 Specify delay between the physical interface going down and the backup being enabled, and between the physical interface coming back up and the backup being disabled.	backup delay enable-delay disable-delay

Dialer Profile for ISDN BRI Backing Up Two Leased Lines Example

The following example shows the configuration of a site that backs up two leased lines using one BRI. Two dialer interfaces are defined. Each serial (leased line) interface is configured to use one of the dialer interfaces as a backup. Both of the dialer interfaces use dialer pool 1, which has physical interface BRI 0 as a member. Thus, physical interface BRI 0 can back up two different serial interfaces and can make calls to two different sites.

interface dialer0

 ip unnumbered loopback0

 encapsulation ppp

 dialer remote-name Remote0

 dialer pool 1

 dialer string 5551212

 dialer-group 1

interface dialer1

 ip unnumbered loopback0

 encapsulation ppp

 dialer remote-name Remote1

 dialer pool 1

 dialer string 5551234

 dialer-group 1

interface bri 0

 encapsulation PPP

 dialer pool-member 1

 ppp authentication chap

interface serial 0

 ip unnumbered loopback0

 backup interface dialer 0

 backup delay 5 10

interface serial 1

 ip unnumbered loopback0

 backup interface dialer1

 backup delay 5 10