Reference Guide

A tracked IPv6 route is considered to match an entry in the routing table only if the
exact IPv6 address and prefix length match a table entry. For example, when
configured as a tracked route, 3333:100:200:300:400::/80 does not match routing
table entry 3333:100:200:300::/64. If no route-table entry has the exact IPv6
address and prefix length, the status of the tracked route is considered to be
DOWN.
When you configure the threshold of an IPv6 route metric as a tracked object, the
UP/DOWN state of the tracked route is also determined by the current metric for
the route in the routing table.
To provide a common tracking interface for different clients, route metrics are
scaled in the range 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. To determine the state of a tracked route, the
resulting scaled value is compared against the configured threshold values 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.
Configure the UP and DOWN thresholds for each tracked IPv6 route 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 ipv6 route – displays information about tracked IPv6 routes,
including configuration, current state, and clients which track the route.
• threshold metric – configures the metric threshold used to determine the UP
and/or DOWN state of a tracked route.
• track resolution ipv6 route – configures the protocol-specific resolution value
used to scale an IPv6 route metric.
track ipv6 route reachability
Configure object tracking on the reachability of an IPv6 route.
Syntax
track object-id ipv6 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.
ipv6-address/
prefix-len
Enter an IPv6 address in X:X:X:X::X format. The valid IPv6
prefix lengths are from /0 to / 128.
Defaults none
1386
Object Tracking