Concept Guide

The following example congures object tracking on the reachability of an IPv6 route:
DellEMC(conf)#track 105 ipv6 route 1234::/64 reachability
DellEMC(conf-track-105)#delay down 5
DellEMC(conf-track-105)#description Headquarters
DellEMC(conf-track-105)#end
DellEMC#show track 105
Track 105
IPv6 route 1234::/64 reachability
Description: Headquarters
Reachability is Down (route not in route table)
2 changes, last change 00:03:03
Conguring track reachability refresh interval
If there is no entry in ARP table or if the next-hop address in the ARP cache ages out for a route tracked for its reachability, an attempt is
made to check if the next-hop address is reachable after a certain refresh interval to see if the next-hop address appear in the ARP cache
before considering it as DOWN.
You can change the refresh interval for which the next-hop address is checked. The default refresh interval is 60 seconds. The object
tracking is done after the default refresh interval everytime and whenever there is a change in reachability state, the next-hop will be
considered as DOWN. The default interval is changed using the track reachability refresh command. You can disable the track
reachability feature by setting the refresh interval to 0.
To change the refresh interval for tracking an IPv4 or IPv6 route, use the following command.
Change the reachability refresh interval for tracking of an IPv4 or IPv6 route.
CONFIGURATION mode
track reachability refresh interval
The refresh interval range is from 0 to 60 seconds. The default is 60 seconds.
Examples of IPv4 and IPv6 Tracking Route Reachability
The following example shows how to change the refresh interval for tracking the reachability of the next-hop:
DellEMC#configure
DellEMC(conf)#track reachability refresh 20
For example, consider that the next-hop address is changed and the track reachability is checked after the set refresh interval (20
seconds). If the reachability to the next-hop address is failed, the system displays the following log stating that the track object state is
changed from UP to DOWN.
Sep 28 11:08:57 %STKUNIT1-M:CP %OTM-6-STATE: Object 2 state transition from Up to Down.
Tracking a Metric Threshold
Use the following commands to congure object tracking on the metric threshold of an IPv4 or IPv6 route.
To remove object tracking, use the no track object-id command.
1 (Optional) Recongure the default resolution value used by the specied protocol to scale the metric for IPv4 or IPv6 routes.
CONFIGURATION mode
track resolution {ip route | ipv6 route} {isis resolution-value | ospf resolution-value}
The range of resolution values is:
• ISIS routes - 1 to 1000. The default is 1.
Object Tracking
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