Deployment Guide

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 – displays information about tracked objects, including configuration, current state, and
clients which track the object.
● threshold metric – configures the metric threshold used to determine the UP and/or DOWN state of a
tracked route.
● track resolution ip route – configures the protocol-specific resolution value used to scale an IPv4
route metric.
track ip route reachability
Configure object tracking on the reachability of an IPv4 route.
C9000 Series
Syntax
track object-id ip route ip-address/prefix-len reachability
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 from 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.
Defaults none
Command Modes CONFIGURATION
Command
History
This guide is platform-specific. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.9(0.0) Introduced on the C9010.
9.8(0.0) Introduced on the S3048-ON and S4048-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 reachability of an IPv4 route. In order for a route’s
reachability 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 prefix length match a table entry. For example, when configured 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
prefix length, the status of the tracked route is considered to be DOWN.
When you configure IPv4 route reachability as a tracked object, the UP/DOWN state of the tracked route
is also determined by the entry of the next-hop address in the address resolution protocol (ARP) cache.
A tracked route is considered to be reachable if there is an ARP cache entry for the route's next-hop
address.
Object Tracking 1141