Setting Tracking Delays; Vrrp Object Tracking - Dell Force10 C150 Configuration Manual

• 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-configurable for each tracked route. 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.
The tracking process uses a protocol-specific resolution value to convert the actual metric in the routing
table to a scaled metric in the range 0 to 255. The resolution value is user-configurable 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 1 to 1000, where the default is 10.
• For OSPF, you can set the resolution in the range 1 to 1592, where the default is 1.
• The resolution value used to map static routes is not configurable. By default, FTOS assigns a metric
of 0 to static routes.
• The resolution value used to map RIP routes is not configurable. The RIP hop-count is automatically
multiplied by 16 to scale it; a RIP metric of 16 (unreachable) scales to 256, which considers the route
to be DOWN. For example, to configure object tracking for a RIP route to be considered UP only if the
RIP hop count is less than or equal to 4, you would configure the UP threshold to be 64 (4 x 16) and
the DOWN threshold to be 65.

Setting Tracking Delays

You can configure an optional UP and/or DOWN timer for each tracked object to set the time delay before
a change in the state of a tracked object is communicated to clients. The configured time delay starts when
the state changes from UP to DOWN or vice-versa.
If the state of an object changes back to its former UP/DOWN state before the timer expires, the timer is
cancelled and the client is not notified. If the timer expires and an object's state has changed, a notification
is sent to the client. For example, if the DOWN timer is running when an interface goes down and comes
back up, the DOWN timer is cancelled and the client is not notified of the event.
If no delay is configured, a notification is sent immediately as soon as a change in the state of a tracked
object is detected. The time delay in communicating a state change is specified in seconds.

VRRP Object Tracking

As a client, VRRP can track up to twenty objects (including route entries, and Layer 2 and Layer 3
interfaces) in addition to the twelve tracked interfaces supported for each VRRP group.
680 | Object Tracking