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Community Member

Changing Network Class

Hi All

Sorry for my lack of knowledge re IOS. I do know that this is wrong and wondering how to change it

router ospf 1


network area 0

network area 29

network area 30

network area 31

That 132 network should be class B. Any tips on how to correct that would be much appreciated.

Thanks in advance

Community Member

Re: Changing Network Class


Step.1 you should enter to OSPF configuration mode

Step.2 delete 132 network

no network area 0

Step.3 add the corrected network

network area 0

Step.3 in the enable mode, save the configuration.

Or Step.2 and Step.3 go together, u can change the wildcard directly.

Community Member

Re: Changing Network Class

I hate to ask but how do I get into OSPF config mode?


config ? something?

Community Member

Re: Changing Network Class



Router#config terminal

Router(config)# router ospf 1


so that u can enter to OSPF mode.

Cisco Employee

Re: Changing Network Class

Hi Paul,

Please be adviced that, it is not mandatory that you need to configure for all class B address. wildcard mask in network command under ospf routing protocol, is just to match the interface IP address and place the same in configured area. For EX:

If you have and address configured in your router which needs to be in area 0, you still can configure "network area 0"


Community Member

Re: Changing Network Class

Hi Paulo,

172 is a class B network but OSPF is a classless protocol. so you can configure any mask depending on your requirement.

You can break a single B class into sevral C class networks.

So first see your requirement and if needed then only delete it.




Re: Changing Network Class

Why do you think it is wrong ? You have to look at the interfaces , maybe that particular network is all they want to advertise . That statement is not neccessarily wrong.

Community Member

Re: Changing Network Class

Well I think it is wrong because the network is using IP's 132.1.1.* - 132.1.7.*

Am I right?

Hall of Fame Super Bronze

Re: Changing Network Class

If you want to enable OSPF on interfaces with subnets mentioned above (132.1.1.* - 132.1.7.*) then yes, it won't work with the current network statement under OSPF.

network area 0

should do the job.

Keep in mind, the list of networks under the OSPF process do not represent the networks that are being advertised -in transit- but the list of interfaces this device has, which you want to enable OSPF.

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