Users Guide

When you configure 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 different 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 configured 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 configure 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 notification of a
change in the state of a tracked object is sent when a metric value crosses a configured threshold.
Related
Commands
• show track – display information about tracked objects, including configuration, current state, and
clients which track the object.
• threshold metric – configure the metric threshold used to determine the UP and/or DOWN state of a
tracked route.
• track resolution ip route – configure the protocol-specific resolution value used to scale an IPv4
route metric.
track ip host reachability
Configure object tracking on the reachability of an IPv4 host.
Syntax
track object-id ip host host-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/
prefix-len
Enter an IPv4 address in dotted decimal format. The valid IPv4 prefix lengths are
from /0 to /32.
vrf vrf-name (Optional) You can configure 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
This guide is platform-specific. For command information about other platforms, see the relevant Dell
Networking OS Command Line Reference 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 S4820T, S4810, S6000, S5000, Z9000, Z9500, IOA, and MXL.
Object Tracking 1102