Installing and Administering Internet Services

292 Chapter 8

Conﬁguring gated

Importing and Exporting Routes

The import and export control statements allow you to propagate

routes from one routing protocol to another. Routes are imported into a

gated forwarding table and exported out to the routing protocols.

Type man 4 gated.conf for more information on import and export

statements.

import Statements

import statements restrict or control how routes are imported to the

gated forwarding table. Once routes are imported to the gated

forwarding table, they can be exported to the routing protocols. You can

use import statements to do the following:

• Prevent routes from being imported into the gated forwarding table

by using a restrict clause.

• Assign a preference value to use when comparing a route to other

routes from other protocols. The route with the lowest preference

available at any given route is installed in the gated forwarding

table. The default preferences are conﬁgured by the individual

protocols.

The format of import statements varies depending on the protocol from

which you are importing routes.

With OSPF, you can apply import statements only to OSPF ASE routes.

All OSPF intra-area and inter-area routes are imported into the gated

forwarding table and with an assigned preference of 10.

export Statements

export statements determine which routes are exported from the gated

forwarding table to the routing protocols. You can also restrict which

routes are exported and assign metrics (values used for route selection)

to be applied to the routes after they have been exported.

The format of the export statement varies according to the protocol to

which you are exporting routes and the original protocol used to build

the routes you are exporting.