Users Guide
Version Description
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000-ON.
8.3.12.0 Introduced on the S4810.
8.4.1.0 Introduced.
Usage Information
Use this command to create an object that tracks the UP and/or DOWN threshold of an IPv4 route metric. In order
for a route’s metric to be tracked, the route must appear as an entry in the routing table.
A tracked IPv4 route is considered to match an entry in the routing table only if the exact IPv4 address and prex
length match a table entry. For example, when congured as a tracked route, 10.0.0.0/24 does not match the
routing table entry 10.0.0.0/8. If no route-table entry has the exact IPv4 address and prex length, the status of the
tracked route is considered to be DOWN.
When you congure the threshold of an IPv4 route metric as a tracked object, the UP/DOWN state of the tracked
route is also determined by the current metric for the route in the routing table.
To provide a common tracking interface for dierent clients, route metrics are scaled in the range 0 to 255, where
0 is connected and 255 is inaccessible. The scaled metric value communicated to a client always considers a lower
value to have priority over a higher value. The resulting scaled value is compared against the congured threshold
values to determine the state of a tracked route as follows:
• If the scaled metric for a route entry is less than or equal to the UP threshold, the state of a route is UP.
• If the scaled metric for a route is greater than or equal to the DOWN threshold or the route is not entered in
the routing table, the state of a route is DOWN.
You congure the UP and DOWN thresholds for each tracked route by using the threshold metric command.
The default UP threshold is 254; the default DOWN threshold is 255. The notication of a change in the state of a
tracked object is sent when a metric value crosses a congured threshold.
Related Commands
• show track – display information about tracked objects, including conguration, current state, and clients which
track the object.
• threshold metric – congure the metric threshold used to determine the UP and/or DOWN state of a tracked
route.
• track resolution ip route – congure the protocol-specic resolution value used to scale an IPv4 route metric.
track ip route reachability
Congure object tracking on the reachability of an IPv4 route.
Syntax
track object-id ip route ip-address/prefix-len reachability [vrf vrf-name]
To return to the default setting, use the no track object-id command.
Parameters
object-id Enter the ID number of the tracked object. The range is 1 to 500.
ip-address/ prex-
len
Enter an IPv4 address in dotted decimal format. The valid IPv4 prex lengths are from /0
to /32.
990 Object Tracking