LevelOne GTL-2691 - Manual (Page 674)

C HAPTER 20 | Unicast Routing
Configuring the Open Shortest Path First Protocol (Version 2)
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◆ Auto Cost – Calculates the cost for an interface by dividing the
reference bandwidth by the interface bandwidth. The reference
bandwidth is defined in Mbits per second. (Range: 1-4294967)
By default, the cost is 0.1 for Gigabit ports, and 0.01 for 10 Gigabit
ports. A higher reference bandwidth can be used for aggregate links to
indicate preferred use as a lower cost interface.
◆ SPF Hold Time – The hold time between making two consecutive
shortest path first (SPF) calculations. (Range: 0-65535 seconds;
Default: 10 seconds)
Setting the SPF holdtime to 0 means that there is no delay between
consecutive calculations.
◆ SPF Delay Time – The delay after receiving a topology change
notification and starting the SPF calculation. (Range: 0-65535 seconds;
Default: 5 seconds)
Using a low value for the delay and hold time allows the router to
switch to a new path faster, but uses more CPU processing time.
◆ Default Metric – The default metric for external routes imported from
other protocols. (Range: 0-16777214; Default: 20)
A default metric must be used to resolve the problem of redistributing
external routes from other protocols that use incompatible metrics.
This default metric does not override the metric value set on the
Redistribute configuration screen (see page 687 ). When a metric value
has not been configured on the Redistribute page, the default metric
configured on the System configuration page sets the metric value to
be used for all imported external routes.
Default Information
◆ Originate Default Route 12 – Generates a default external route into
an autonomous system. Note that the Advertise Default Route field
must also be properly configured. (Default: Disabled)
When this feature is used to redistribute routes into a routing domain
(that is, an Autonomous System), this router automatically becomes an
Autonomous System Boundary Router (ASBR). This allows the router to
exchange routing information with boundary routers in other
autonomous systems to which it may be attached. If a router is
functioning as an ASBR, then every other router in the autonomous
system can learn about external routes from this device.
Figure 426: AS Boundary Router
12. These are configured with the default-information originate command.
AS 1 ASBR AS 2 ASBR