IP Routing Features

Configuring OSPF

Example: Here is an example of the commands to set up several OSPF areas. HPswitch(ospf)# area 192.5.1.0

HPswitch(ospf)# area 200.5.0.0

HPswitch(ospf)# area 195.5.0.0

HPswitch(ospf)# area 0.0.0.0

HPswitch(ospf)# write memory

 

Syntax: area <num> <ip-addr> [stub <cost> [no-summary]]

 

The <num> <ip-addr>parameter specifies the area number, which can be a

 

number or in IP address format. If you specify a number, the number can be

 

from 0 – 4,294,967,295.

 

The <cost> specifies the cost of the default route to be injected into the stub

 

area, if this routing switch is an ABR. The value can be from 1 – 16,777,215. If

 

you configure a stub area, you must specify the cost. There is no default.

 

Normal areas do not use the cost parameter.

 

The no-summaryparameter applies only to stub areas and disables summary

 

LSAs from being sent into the area. See “Assign a Totally Stubby Area” below.

 

 

N o t e

You can assign subnets individually to areas. The limit on the number of areas

 

is 16.

 

Assign a Totally Stubby Area

 

 

By default, the Series 5300XL Switch sends summary LSAs (LSA type 3) into

 

stub areas. You can further reduce the number of link state advertisements

 

(LSA) sent into a stub area by configuring the Series 5300XL Switch to stop

 

sending summary LSAs (type 3 LSAs) into the area. You can disable the

 

summary LSAs when you are configuring the stub area or later after you have

 

configured the area.

 

This feature disables origination of summary LSAs, but the Series 5300XL

 

Switch still accepts summary LSAs from OSPF neighbors and floods them to

 

other neighbors. The Series 5300XL Switch can form adjacencies with other

 

routers regardless of whether summarization is enabled or disabled for areas

 

on each Series 5300XL Switch.

 

When you enter a command to disable the summary LSAs, the change takes

 

effect immediately. If you apply the option to a previously configured area, the

 

Series 5300XL Switch flushes all of the summary LSAs it has generated (as an

 

ABR) from the area.

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