Cisco Systems ME3400G2CSA Configuring OSPF

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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide

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Chapter32 Configuring IP Unicast Routing Configuring OSPF

Routers connected to broadcast-type IP networks and using distance-vector routing protoc ols no rm all y

use the split-horizon mechanism to reduce the possibility of routing loops. Split horizon blocks

information about routes from being advertised by a router on a ny interface from which that information

originated. This feature can optimize communication among multiple routers, especia lly wh en li nks a re

broken.

Note In general, Cisco does 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, see the “OSPF Commands” chapter of the Cisco IOS IP Command

Reference, Volume 2 of 3: Routing Protocols, Release 12.2.

Note OSPF classifies different media into broadcast, nonbroadcast, and point-to-point networks. The switch

supports broadcast 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).

Command Purpose

Step1 configure terminal Enter global configuration mode.

Step2 interface interface-id Enter interface configuration mode, and specify the interface to

configure.

Step3 no shutdown Enable the interface if necessary. By default, UNIs are disabled and

NNIs are enabled.

Step4 ip address ip-address subnet-mask Configure the IP address and IP subnet.

Step5 no ip split-horizon Disable split horizon on the interface.

Step6 end Return to privileged EXEC mode.

Step7 show ip interface interface-id Verify your entries.

Step8 copy running-config startup-config (Optional) Save your entries in the configuration file.