Setup Guide

a route tracked for its reachability, an attempt is made to regenerate the ARP cache entry to see if the next-hop address appears
before considering the route DOWN.
• By comparing the threshold for a route’s metric with current entries in the route table.
The UP/DOWN state of the tracked route is determined by the threshold for the current value of the route metric in the routing table.
To provide a common tracking interface for dierent clients, route metrics are scaled in the range from 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 congured 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.
The UP and DOWN thresholds are user-congurable for each tracked route. The default UP threshold is 254; the default DOWN
threshold is 255. The notication of a change in the state of a tracked object is sent when a metric value crosses a congured
threshold.
The tracking process uses a protocol-specic resolution value to convert the actual metric in the routing table to a scaled metric in the
range from 0 to 255. The resolution value is user-congurable and calculates the scaled metric by dividing a route’s cost by the
resolution value set for the route type:
– For ISIS, you can set the resolution in the range from 1 to 1000, where the default is 10.
– For OSPF, you can set the resolution in the range from 1 to 1592, where the default is 1.
– The resolution value used to map static routes is not congurable. By default, Dell EMC Networking OS assigns a metric of 0 to
static routes.
– The resolution value used to map RIP routes is not congurable. The RIP hop-count is automatically multiplied by 16 to scale it. For
example, a RIP metric of 16 (unreachable) scales to 256, which considers a route to be DOWN.
Tracking Route Reachability
Use the following commands to congure object tracking on the reachability of an IPv4 or IPv6 route.
To remove object tracking, use the no track object-id command.
1 Congure object tracking on the reachability of an IPv4 or IPv6 route.
CONFIGURATION mode
track object-id {ip route ip-address/prefix-len | ipv6 route ipv6-address/prefix-len}
reachability [vrf vrf-name]
Valid object IDs are from 1 to 500.
Enter an IPv4 address in dotted decimal format; valid IPv4 prex lengths are from / 0 to /32.
Enter an IPv6 address in X:X:X:X::X format; valid IPv6 prex lengths are from / 0 to /128.
(Optional) E-Series only: For an IPv4 route, you can enter a VRF name to specify the virtual routing table to which the tracked route
belongs.
2 (Optional) Congure the time delay used before communicating a change in the status of a tracked route.
OBJECT TRACKING mode
delay {[up seconds] [down seconds]}
Valid delay times are from 0 to 180 seconds.
The default is 0.
3 (Optional) Identify the tracked object with a text description.
Object Tracking
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