Administrator Guide

Configuring 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.
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.
Displaying Tracked Objects
To display the currently configured objects used to track Layer 2 and Layer 3 interfaces, and IPv4 and IPv6 routes, use the
following show commands.
To display the configuration and status of currently tracked Layer 2 or Layer 3 interfaces, IPv4 or IPv6 routes, or a VRF
instance, use the show track command. You can also display the currently configured per-protocol resolution values used to
scale route metrics when tracking metric thresholds.
● Display the configuration and status of currently tracked Layer 2 or Layer 3 interfaces, IPv4 or IPv6 routes, and a VRF
instance.
show track [object-id [brief] | interface [brief] [vrf vrf-name] | ip route [brief] [vrf
vrf-name] | resolution | vrf vrf-name [brief] | brief]
● Display the tracking configuration of a specified object or all objects that are currently configured on the router.
show running-config track [object-id]
Example of the show track command.
Dell#show track
Track 1
IP route 23.0.0.0/8 reachability
Reachability is Down (route not in route table)
2 changes, last change 00:16:08
Tracked by:
Track 2
IPv6 route 2040::/64 metric threshold
Metric threshold is Up (STATIC/0/0)
5 changes, last change 00:02:16
Metric threshold down 255 up 254
First-hop interface is GigabitEthernet 13/2
Tracked by:
VRRP GigabitEthernet 7/30 IPv6 VRID 1
Track 3
636
Object Tracking