Cisco Systems 78-11741-02 manual Complex Ospf Configuration for ABR Examples, IPC-249

Configuring OSPF

OSPF Configuration Examples

router bgp 109 network 131.108.0.0 network 10.0.0.0

neighbor 11.0.0.6 remote-as 110

Complex OSPF Configuration for ABR Examples

The following example configuration accomplishes several tasks in setting up an ABR. These tasks can be split into two general categories:

•Basic OSPF configuration

•Route redistribution

The specific tasks outlined in this configuration are detailed briefly in the following descriptions. Figure 43 illustrates the network address ranges and area assignments for the interfaces.

Figure 43 Interface and Area Specifications for OSPF Example Configuration

Network address range:

192.168.110.0 through 192.168.110.255 Area ID: 192.168.110.0

					Network address range:
	Router A		E0		172.19.251.0 through 172.19.251.255
		E3		E1	Area ID: 0
					Configured as backbone area
				E2
Network address range:
10.56.0.0 through 10.56.255.255
	Network address range:
Area ID: 10.0.0.0
Configured as stub area	172.19.254.0 through 172.19.254.255					S1031a
	Configured as backbone area
	Area ID: 0

The basic configuration tasks in this example are as follows:

•Configure address ranges for Ethernet interface 0 through Ethernet interface 3.

•Enable OSPF on each interface.

•Set up an OSPF authentication password for each area and network.

•Assign link-state metrics and other OSPF interface configuration options.

•Create a stub area with area ID 36.0.0.0. (Note that the authentication and stub options of the area router configuration command are specified with separate area command entries, but can be merged into a single area command.)

•Specify the backbone area (area 0).

Configuration tasks associated with redistribution are as follows:

•Redistribute IGRP and RIP into OSPF with various options set (including metric-type, metric, tag, and subnet).

•Redistribute IGRP and OSPF into RIP.

The following is an example OSPF configuration:

Cisco IOS IP Configuration Guide

IPC-249