Setup Guide

To congure object tracking on the routing status of a Layer 3 interface, use the following commands.

1 Congure object tracking on the routing status of an IPv4 or IPv6 interface.

CONFIGURATION mode

track object-id interface interface {ip routing | ipv6 routing}

Valid object IDs are from 1 to 500.

2 (Optional) Congure the time delay used before communicating a change in the status of a tracked interface.

OBJECT TRACKING mode

delay {[up seconds] [down seconds]}

Valid delay times are from 0 to 180 seconds.

The default is 0.

3 (Optional) Identify the tracked object with a text description.

OBJECT TRACKING mode

description text

The text string can be up to 80 characters.

4 (Optional) Display the tracking conguration and the tracked object’s status.

EXEC Privilege mode

show track object-id

Examples of Conguring Object Tracking for an IPv4 or IPv6 Interface

The following is an example of conguring object tracking for an IPv4 interface:

The following is an example of conguring object tracking for an IPv6 interface:

Track an IPv4/IPv6 Route

You can create an object that tracks the reachability or metric of an IPv4 or IPv6 route.

You specify the route to be tracked by its address and prex-length values. Optionally, for an IPv4 route, you can enter a VRF instance

name if the route is part of a VPN routing and forwarding (VRF) table. The next-hop address is not part of the denition of a tracked IPv4/

IPv6 route.

In order for an route’s reachability or metric to be tracked, the route must appear as an entry in the routing table. A tracked route is

considered to match an entry in the routing table only if the exact IPv4 or IPv6 address and prex length match an entry in the table. For

example, when congured as a tracked route, 10.0.0.0/24 does not match the routing table entry 10.0.0.0/8. Similarly, for an IPv6 address,

3333:100:200:300:400::/80 does not match routing table entry 3333:100:200:300::/64. If no route-table entry has the exact IPv4/IPv6

address and prex length, the tracked route is considered to be DOWN.

In addition to the entry of a route in the routing table, you can congure the UP/DOWN state of a tracked route to be determined in the

following ways:

• By the reachability of the route's next-hop router.

The UP/DOWN state of the route is determined by the entry of the next-hop address in the ARP cache. A tracked route is considered

to be reachable if there is an ARP cache entry for the route's next-hop address. If the next-hop address in the ARP cache ages out for

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Object Tracking