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Catalyst 3560 Switch Software Configuration Guide
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Chapter 30 Configuring IP Unicast Routing
Configuring OSPF
Note
In general, we do not recommend disabling split horizon unless you are certain that your application
requires it to properly advertise routes.
Beginning in privileged EXEC mode, follow these steps to disable split horizon on the interface:
To enable the split horizon mechanism, use the ip split-horizon interface configuration command.
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 3560 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:
•
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 1587are supported.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter interface configuration mode, and specify the interface to
configure.
Step 3
ip address ip-address subnet-mask
Configure the IP address and IP subnet.
Step 4
no ip split-horizon
Disable split horizon on the interface.
Step 5
end
Return to privileged EXEC mode.
Step 6
show ip interface interface-id
Verify your entries.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.