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New Member

ospf config

Hi,

below is my ospf setting,

router ospf 100

network 192.168.1.0 0.0.0.255 area 0

network 172.16.1.5 0.0.0.3 area 1

what is different if I change to

"network 172.16.1.4 0.0.0.3 area 1"

which one is better?

network 172.16.1.5 0.0.0.3 area 1

or

network 172.16.1.4 0.0.0.3 area 1

rdgs

2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Blue

Re: ospf config

Anita

Generally it would be either

network 172.16.1.5 0.0.0.0 area 1

OR

network 172.16.1.4 0.0.0.3 area 1

The mask just allows you to be very specific about which interfaces to run OSPF on.

As to which is better, well in this case it doesn't make a lot of difference because 172.16.1.4 0.0.0.3 only covers 172.16.1.4 -> 172.16.1.7.

Jon

Hall of Fame Super Silver

Re: ospf config

Anita

It should be the same result.

I believe that you can type it in as:

network 172.16.1.5 0.0.0.3 area 1

but when you do show run I believe that you will find that IOS has translated and it will show up as:

network 172.16.1.4 0.0.0.3 area 1

This is because the address you want to input and the mask are inconsistent. The mask of 0.0.0.3 indicates a subnet address with mask of 255.255.255.252 and IOS will translate what you input to show the subnet address if you use the "subnet" nask.

HTH

Rick

3 REPLIES
Hall of Fame Super Blue

Re: ospf config

Anita

Generally it would be either

network 172.16.1.5 0.0.0.0 area 1

OR

network 172.16.1.4 0.0.0.3 area 1

The mask just allows you to be very specific about which interfaces to run OSPF on.

As to which is better, well in this case it doesn't make a lot of difference because 172.16.1.4 0.0.0.3 only covers 172.16.1.4 -> 172.16.1.7.

Jon

New Member

Re: ospf config

Hi,

can I config as

network 172.16.1.5 0.0.0.3 area 1

Is it the same result?

rdgs

Hall of Fame Super Silver

Re: ospf config

Anita

It should be the same result.

I believe that you can type it in as:

network 172.16.1.5 0.0.0.3 area 1

but when you do show run I believe that you will find that IOS has translated and it will show up as:

network 172.16.1.4 0.0.0.3 area 1

This is because the address you want to input and the mask are inconsistent. The mask of 0.0.0.3 indicates a subnet address with mask of 255.255.255.252 and IOS will translate what you input to show the subnet address if you use the "subnet" nask.

HTH

Rick

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