The track 1 interface FastEthernet1/1 ip routing command will track whether IP routing is enabled, the interface line protocol is up, and the interface IP address is configured. If any of the three criteria are not met, the tracked interface is considered to be down. To track whether IPv6 routing is enabled, the line protocol is up, and the interface IPv6 address is configured, you could issue the track 1 interface FastEthernet1/1 ipv6 routing command.

The track 1 interface FastEthernet1/1 lineprotocol command will track whether the interface line protocol is up. However, it will not track whether IP routing is enabled and the interface IP address is configured.

The track 1 ip route 10.10.10.0/24 reachability command will track whether the destination network is reachable. The subnet address must be issued in Classless InterDomain Routing (CIDR) notation.

The track 1 ip route 10.10.10.0/24 metric threshold command will track whether the metric threshold is exceeded. By default, a metric value of 254 or less is considered to be accessible and a metric value of 255 is considered to be inaccessible. The threshold metric up upvalue down downvalue command can be used to change the default metric threshold values.