Configuring ospf – Cisco 15327 User Manual

Page 167

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11-9

Ethernet Card Software Feature and Configuration Guide, R7.2

Chapter 11 Configuring Networking Protocols

Configuring OSPF

To disable IP summarization, use the no ip summary-address rip router configuration command.

Note

If split horizon is enabled, neither autosummary nor interface summary addresses (those configured with
the ip summary-address rip router configuration command) are advertised.

Configuring OSPF

This section briefly describes how to configure the Open Shortest Path First (OSPF) protocol. For a
complete description of the OSPF commands, refer to the “OSPF Commands” chapter of the Cisco IOS
IP and IP Routing Command Reference
publication.

OSPF is an 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, the OSPF MIB.

The Cisco implementation conforms to the OSPF Version 2 specifications with these key features:

Stub areas—Definition of stub areas is supported.

Route redistribution—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 and export
routes learned through protocols such as EIGRP and RIP.

Authentication—Plain text and MD5 authentication among neighboring routers within an area are
supported.

Routing interface parameter—Configurable parameters supported include interface output cost,
retransmission interval, interface transmit delay, router priority, router dead and hello intervals, and
authentication key.

Virtual links—Virtual links are supported.

Not-so-stubby-area (NSSA)—RFC 1587.

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.

Table 11-2

shows the default OSPF configuration.

Step 4

Router(config-if)# ip

summary-address rip

ip-address

ip-network-mask

Configures the IP address to be summarized and the IP
network mask.

Step 5

Router(config-if)# no ip split

horizon

Disables split horizon on the interface.

Step 6

Router(config-if)# end

Returns to privileged EXEC mode.

Step 7

Router# show ip interface

interface-id

Verifies your entries.

Step 8

Router# copy running-config

startup-config

(Optional) Saves your entries in the configuration file.

Command

Purpose

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