Reference Guide
A tracked host is reachable if there is an ARP cache entry for the router's next-hop address. An attempt to regenerate the ARP cache
entry occurs if the next-hop address appears before considering the route Down.
1 Congure object tracking in CONFIGURATION mode.
track object-id
2 Enter the host IP address for reachability of an IPv4 or IPv6 route in OBJECT TRACKING mode.
[ip | ipv6] host-ip-address reachability
3 Congure the time delay used before communicating a change in the status of a tracked route in OBJECT TRACKING mode.
delay [up seconds] [down seconds]
4 View the tracking conguration and the tracked object status in EXEC mode.
show track object-id
Congure IPv4 host tracking
OS10 (conf-track-1)# track 2
OS10 (conf-track-2)# ip 1.1.1.1 reachability
OS10 (conf-track-2)# do commit
OS10 (conf-track-2)# do show track 2
IP Host 1.1.1.1 reachability
Reachability is DOWN
1 changes, Last change 2017-04-26T06:45:31Z
OS10 (conf-track-2)#
Congure IPv6 host tracking
OS10 (conf-track-2)# track 3
OS10 (conf-track-3)# ipv6 20::20 reachability
OS10 (conf-track-3)# delay up 20
OS10 (conf-track-3)# do commit
OS10 (conf-track-3)# do show track 3
IP Host 20::20 reachability
Reachability is DOWN
1 changes, Last change 2017-04-26T06:47:04Z
OS10 (conf-track-3)#
Set tracking delays
You can congure an optional Up and/or Down timer for each tracked object. The timer allows you to set the time delay before a change in
the state of a tracked object is communicated to clients. The time delay starts when the state changes from Up to Down or from Down to
Up.
If the state of an object changes back to its former Up or Down state before the timer expires, the timer is canceled without notifying the
client. If the timer expires and an object’s state has changed, a notication is sent to the client. For example, if the Down timer is running
and an interface goes down then comes back up, the Down timer is canceled. The client is not notied of the event.
If you do not congure a delay, a notication is sent when a change in the state of a tracked object is detected. The time delay in
communicating a state change is specied in seconds.
Object tracking
As a client, VRRP can track up to 20 interface objects plus 12 tracked interfaces supported for each VRRP group. You can assign a unique
priority-cost value from 1 to 254 to each tracked VRRP object or group interface.
The priority cost is subtracted from the VRRP group priority if a tracked VRRP object is in a Down state. If a VRRP group router acts as
owner-master, the run-time VRRP group priority remains xed at 255. Changes in the state of a tracked object have no eect.
Layer 3
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