Configuring Ospf - Cisco Catalyst 3550 series Software Configuration Manual

Chapter 31 Configuring IP Unicast Routing

Configuring OSPF

This section briefly describes how to configure Open Shortest Path First (OSPF). For a complete
description of the OSPF commands, refer to the "OSPF Commands" chapter of the Cisco IOS IP and IP
Routing Command Reference for Release 12.1.
Note OSPF classifies different media into broadcast, nonbroadcast, and point-to-point networks. The Catalyst
3550 switch supports broadcast (Ethernet, Token Ring, and FDDI) and point-to-point networks (Ethernet
interfaces configured as point-to-point links).
OSPF is an Interior Gateway Protocol (IGP) designed expressly for IP networks, supporting IP
subnetting and tagging of externally derived routing information. OSPF also allows packet
authentication and uses IP multicast when sending and receiving packets. The Cisco implementation
supports RFC 1253, OSPF management information base (MIB).
The Cisco implementation conforms to the OSPF Version 2 specifications with these key features:
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OSPF typically requires coordination among many internal routers, area border routers (ABRs)
connected to multiple areas, and autonomous system boundary routers (ASBRs). The minimum
configuration would use all default parameter values, no authentication, and interfaces assigned to areas.
If you customize your environment, you must ensure coordinated configuration of all routers.
This section briefly describes how to configure OSPF. It includes this information:
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Definition of stub areas is supported.
Routes learned through any IP routing protocol can be redistributed into another IP routing protocol.
At the intradomain level, this means that OSPF can import routes learned through IGRP and RIP.
OSPF routes can also be exported into IGRP and RIP.
Plain text and MD5 authentication among neighboring routers within an area is supported.
Configurable routing interface parameters include interface output cost, retransmission interval,
interface transmit delay, router priority, router dead and hello intervals, and authentication key.
Virtual links are supported.
Not-so-stubby-areas (NSSAs) per RFC 1587 are supported.
Default OSPF Configuration, page 31-30
Configuring Basic OSPF Parameters, page 31-31
Configuring OSPF Interfaces, page 31-32
Configuring OSPF Area Parameters, page 31-33
Configuring Other OSPF Parameters, page 31-34
Changing LSA Group Pacing, page 31-36
Configuring a Loopback Interface, page 31-36
Monitoring OSPF, page 31-37
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring OSPF
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