Users Guide

Parameters
object-id Enter the ID number of the tracked object. The range is 1 to 500.
ip-address/ prex-
len
Enter an IPv4 address in dotted decimal format. The valid IPv4 prex lengths are
from /0 to /32.
vrf vrf-name (Optional) E-Series only: You can congure a VPN routing and forwarding (VRF)
instance to specify the virtual routing table to which the tracked route belongs.
Defaults none
Command Modes CONFIGURATION
Command History
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
prex length match a table entry. 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. If no route-table entry has the exact IPv4 address and prex length,
the status of the tracked route is considered to be DOWN.
When you congure 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 dierent 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 congured 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 congure 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 notication of a
change in the state of a tracked object is sent when a metric value crosses a congured threshold.
Related Commands
• show track – displays information about tracked objects, including conguration, current state, and
clients which track the object.
• threshold metric – congures the metric threshold used to determine the UP and/or DOWN state of a
tracked route.
• track resolution ip route – congures the protocol-specic resolution value used to scale an IPv4 route
metric.
Object Tracking
1019