Configuring Metric Parameters - Foundry Networks Switch and Router Installation And Configuration Manual

Configuring Metric Parameters

By default, a Foundry Layer 3 Switch port increases the cost of a RIP route that is learned on the port by one. You
can configure individual ports to add more than one to a learned route's cost. In addition, you can configure a RIP
offset list to increase the metric for learned or advertised routes based on network address.
Changing the Cost of Routes Learned on a Port
By default, a Foundry Layer 3 Switch port increases the cost of a RIP route that is learned on the port. The Layer
3 Switch increases the cost by adding one to the route's metric before storing the route.
You can change the amount that an individual port adds to the metric of RIP routes learned on the port. To do so,
use either of the following methods.
NOTE: RIP considers a route with a metric of 16 to be unreachable. Use this metric only if you do not want the
route to be used. In fact, you can prevent the Layer 3 Switch from using a specific port for routes learned though
that port by setting its metric to 16.
USING THE CLI
To increase the cost a port adds to RIP routes learned in that port, enter commands such as the following:
BigIron(config)# interface ethernet 6/1
BigIron(config-if-6/1)# ip metric 5
This commands configure port 6/1 to add 5 to the cost of each route learned on the port.
Syntax: ip metric <1-16>
USING THE WEB MANAGEMENT INTERFACE
1. Log on to the device using a valid user name and password for read-write access. The System configuration
panel is displayed.
2. Click on the plus sign next to Configure in the tree view to expand the list of configuration options.
3. Click on the plus sign next to IP in the tree view to expand the list of IP option links.
4. Click on the Interface link to display the interface table.
5. Click on the Modify button in the row for the port.
6. Enter a value from 1 – 16 for the metric.
7. Click the Add button to save the change to the device's running-config file.
8. To configure settings for another port, select the port (and slot, if applicable) and go to step 6.
9. Select the Save link at the bottom of the dialog. Select Yes when prompted to save the configuration change
to the startup-config file on the device's flash memory.
Configuring a RIP Offset List
A RIP offset list allows you to add to the metric of specific inbound or outbound routes learned or advertised by
RIP. RIP offset lists provide a simple method for adding to the cost of specific routes and therefore biasing the
Layer 3 Switch's route selection away from those routes.
An offset list consists of the following parameters:
• An ACL that specifies the routes to which to add the metric.
• The direction:
• In applies to routes the Layer 3 Switch learns from RIP neighbors.
• Out applies to routes the Layer 3 Switch is advertising to its RIP neighbors.
• The type and number of a specific port to which the offset list applies (optional).
December 2000
Configuring RIP
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