Cisco Cisco IOS Software Release 12.4(9)T

The EOT Support for Carrier Delay feature enables Enhanced Object Tracking (EOT) to consider the 
carrier-delay timer when tracking the status of an interface.

If a link fails, by default there is a two-second timer that must expire before an interface and the 
associated routes are declared as being down. If a link goes down and comes back up before the carrier 
delay timer expires, the down state is effectively filtered, and the rest of the software on the switch is not 
aware that a link-down event occurred. You can configure the carrier-delay seconds command in 
interface configuration mode to extend the timer up to 60 seconds. 

When Enhanced Object Tracking (EOT) is configured on an interface, the tracking may detect the 
interface is down before a configured carrier-delay timer has expired. This is because EOT looks at the 
interface state and does not consider the carrier delay timer. Use the carrier-delay command in tracking 
configuration mode to enable tracking to consider the carrier-delay timer configured on an interface.

Configuration information is included in the “Configuring Enhanced Object Tracking” chapter of the 
IP Application Services Configuration Guide, Cisco IOS Release 12.4T,

at the following URL:

The following sections provide information about this feature:

EOT Support for Carrier Delay

Tracking the Line-Protocol State of an Interface

Tracking the IP-Routing State of an Interface

Interface IP Routing: Example

For a complete list of features included in the “Configuring Enhanced Object Tracking” module, refer 
to the Feature Information Table located toward the end of the module.

Command reference information is included in the IP Application Services Command Reference at the 
following URL:

The following commands are new or modified for this feature: