HP-UX Routing Services Administrator's Guide HP-UX 11i v2, HP-UX 11i v3 (B2355-91153, November 2011)

Controlling RIP Traffic
This section describes configuration options for RIP routing information sent by gated from the
node. Use these options to hide all or part of your network from other networks or to limit network
traffic.
The RIP protocol definition in the /etc/gated.conf file contains the following two options for
limiting RIP routing information exported by gated:
• The noripout clause in the interface definition informs gated not to send any RIP information
through the listed interfaces.
• The sourcegateways clause informs gated to send RIP information directly to the specified
routers.
See “RIP Protocol Statement” (page 22) for more information about these clauses.
The options for limiting RIP routing information imported by gated in the RIP protocol definition
in the /etc/gated.conf file are as follows:
• The noripin clause in the interface definition informs gated not to process RIP information
received through the listed interfaces.
• The trustedgateways clause informs gated to listen to RIP information received only from
the specified routers.
See “RIP Protocol Statement” (page 22) for more information about these clauses.
You can also use the gated import and export statements to restrict and control the route
information propagated from one routing protocol to another. See “Importing and Exporting Routes”
(page 47) for more information.
Configuring the OSPF Protocol
Open Shortest Path First (OSPF) is a link-state routing protocol that distributes routing information
between routers in a single autonomous system (AS). Each OSPF router transmits a packet with a
description of its local links to all other OSPF routers. The distributed database is built from the
collected descriptions. Using the database information, each router constructs its own routing table
of shortest paths from itself to each destination in the AS.
OSPF allows you to organize routers, networks, and subnetworks within an AS into subsets called
areas. An area is a grouping of logically contiguous networks and hosts. Instead of maintaining
a topological database of the entire AS, routers in an area maintain the topology for only the area
in which they reside. Therefore, all routers belonging to an area must be consistent in their
configuration of the area. The topology of an area is hidden from systems that are not part of the
area. The creation of separate areas can help minimize overall routing traffic in the AS. Figure 6
shows an example of three separate areas defined for an AS.
Configuring the OSPF Protocol 27