Changing The Administrative Distance - Foundry Networks FESX Manual

FastIron SuperX Router(config)# interface ethernet 6/1
FastIron SuperX Router(config-if-6/1)# ip metric 5
These commands configure port 6/1 to add 5 to the cost of each route learned on the port.
Syntax: ip metric <1-16>
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).
The software adds the offset value to the routing metric (cost) of the routes that match the ACL. If a route matches
both a global offset list and an interface-based offset list, the interface-based offset list takes precedence. The
interface-based offset list's metric is added to the route in this case.
You can configure up to 24 global RIP offset lists and up to 24 RIP offset lists on each interface.
To configure a global RIP offset list, enter commands such as the following:
FastIron SuperX Router(config)# access-list 21 deny 160.1.0.0 0.0.255.255
FastIron SuperX Router(config)# access-list 21 permit any
FastIron SuperX Router(config)# router rip
FastIron SuperX Router(config-rip-router)# offset-list 21 out 10
The commands in this example configure a standard ACL. The ACL matches on all IP networks except 160.1.x.x.
When the Layer 3 Switch advertises a route that matches ACL 21, the offset list adds 10 to the route's metric.
Syntax: [no] <acl-number-or-name> in | out offset [ethernet [<slotnum>/]<portnum>]
In the following example, the Layer 3 Switch uses ACL 21 to add 10 to the metric of routes received on Ethernet
port 2/1.
FastIron SuperX Router(config-rip-router)# offset-list 21 in ethernet 2/1

Changing the Administrative Distance

By default, the Layer 3 Switch assigns the default RIP administrative distance (120) to RIP routes. When
comparing routes based on administrative distance, the Layer 3 Switch selects the route with the lower distance.
You can change the administrative distance for RIP routes.
NOTE: See "Changing Administrative Distances" on page 21-29 for a list of the default distances for all route
sources.
To change the administrative distance for RIP routes, enter a command such as the following:
FastIron SuperX Router(config-rip-router)# distance 140
This command changes the administrative distance to 140 for all RIP routes.
Syntax: [no] distance <num>
December 2005 © Foundry Networks, Inc.
Configuring RIP
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