To configure an interface as a secondary or dial backup, use theÂ backup interface command in interface configuration mode. To disable the interface from serving as a backup, use theÂ no form of this command.
CiscoÂ 7200 Series and CiscoÂ 7500 Series Routers Only
backup interface slot/port-adapter/port
noÂ backup interface slot/port-adapter/port
Other Cisco Routers
backup interface type number
noÂ backup interface type number
|slot/port-adapter/port||The chassis slot, port adapter, and port number of the interface to configure as a backup. Include a slash (/) between slot, port-adapter, and port (for example, 1/1/1). See your hardware installation manual for the specific slot, port adapter, and port numbers.|
|Type and port number of the interface being configured as a backup.|
This command is disabled by default.
|11.0||This command was introduced.|
|12.2(33)SRB1||This command was integrated into Cisco IOS Release 12.2(33)SRB1.|
The interface you define with this command can back up only one other interface.
Routers support only serial and ISDN backup interfaces. Access servers support both asynchronous and serial backup interfaces.
In Cisco IOS Release 12.2(33)SRB1 and later releases, you can configure a backup interface for Gigabit Ethernet on the Cisco 7600 router. The configurations on the primary and backup interfaces must match or the backup interface does not work. Note, however, that if the interface configuration includes theÂ xconnect command, you must specify a different virtual circuit ID (VCID) on the primary and backup interfaces.
The following example sets serial 1 as the backup line to serial 0:
interface serial 0
backup interface serial 1
The following example sets gigabitEthernet4/0/1 as the backup interface for gigabitEthernet3/0/1 on the Cisco 7600 router:
interface gigabitEthernet 3/0/1
backup interface gigabitEthernet 4/0/1
|xconnect||Configures a pseudowire for transporting data over the network.|