Chapter 38 Configuring IP Unicast Routing

Configuring OSPF

Beginning in privileged EXEC mode, follow these steps to configure these OSPF parameters:

 

Command

Purpose

Step 1

 

 

configure terminal

Enter global configuration mode.

Step 2

 

 

router ospf process-id

Enable OSPF routing, and enter router configuration mode.

Step 3

 

 

summary-address address mask

(Optional) Specify an address and IP subnet mask for redistributed

 

 

routes so that only one summary route is advertised.

Step 4

 

 

area area-idvirtual-link router-id

(Optional) Establish a virtual link and set its parameters. See the

 

[hello-interval seconds]

“Configuring OSPF Interfaces” section on page 38-29for parameter

 

[retransmit-interval seconds] [trans]

definitions and Table 38-5 on page 38-26for virtual link defaults.

 

[[authentication-key key]

 

 

message-digest-key keyid md5 key]]

 

Step 5

 

 

default-information originate [always]

(Optional) Force the ASBR to generate a default route into the OSPF

 

[metric metric-value][metric-type

routing domain. Parameters are all optional.

 

type-value][route-mapmap-name]

 

Step 6

 

 

ip ospf name-lookup

(Optional) Configure DNS name lookup. The default is disabled.

Step 7

 

 

ip auto-cost reference-bandwidth ref-bw

(Optional) Specify an address range for which a single route will be

 

 

advertised. Use this command only with area border routers.

Step 8

 

 

distance ospf {[inter-area dist1] [inter-area

(Optional) Change the OSPF distance values. The default distance

 

dist2] [external dist3]}

for each type of route is 110. The range is 1 to 255.

Step 9

 

 

passive-interface type number

(Optional) Suppress the sending of hello packets through the

 

 

specified interface.

Step 10

 

 

timers throttle spf spf-delay spf-holdtime

(Optional) Configure route calculation timers.

 

spf-wait

spf-delay—Delay between receiving a change to SPF

 

 

 

 

calculation. The range is from 1 to 600000. miliseconds.

 

 

spf-holdtime—Delay between first and second SPF calculation.

 

 

The range is form 1 to 600000 in milliseconds.

 

 

spf-wait—Maximum wait time in milliseconds for SPF

 

 

calculations. The range is from 1 to 600000 in milliseconds.

Step 11

 

 

ospf log-adj-changes

(Optional) Send syslog message when a neighbor state changes.

Step 12

 

 

end

Return to privileged EXEC mode.

Step 13

 

 

show ip ospf [process-id[area-id]]database

Display lists of information related to the OSPF database for a

 

 

specific router. For some of the keyword options, see the

 

 

“Monitoring OSPF” section on page 38-35.

Step 14

 

 

copy running-config startup-config

(Optional) Save your entries in the configuration file.

 

 

 

 

 

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

 

 

 

 

 

 

OL-9775-02

 

 

38-33

 

 

 

 

 

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Cisco Systems 3750E manual 38-33