ospf area id value

[tuanmnguyen]

My routers are configured ospf area id as decimal value. Need to connect to mainframe which ospf area id configured as ip address format.

If my router area is 22, what will mainframe ospf area would be? 22.22.22.22 ?

[Kevin Dorrell]

No, it will be 0.0.0.22. The OSPF area id is a 32-bit quantity, pure and simple. The dotted decimal format (which looks like an IP address but isn't) is just a convenient way of representing numbers over 255.

Kevin Dorrell

Luxembourg

[tuanmnguyen]

Thanks Kevin,

So if the ospf id is 300, how the dotted decimal format looks like ?

[wkumari]

300 decimal is:

00000000.00000000.000000001.00101100 (expressed as 32 bits)

This is:

0.0.1.45

[tuanmnguyen]

Not 0.0.1.44 ?