cancel
Showing results for
Did you mean:
cancel
Announcements
215
Views
0
5
Replies
Participant

## OSPF area ID in IP address format ??

What is the difference between "area1" and "area 0.0.0.1"??

I'm not sure how to understand the IP address format of Area.

The device is Nexus.

4 ACCEPTED SOLUTIONS

Accepted Solutions

there should not be any difference between 2 ways of doing same thing.

"area 0.0.0.1" means  "area 1"

Regards, ML

Hall of Fame Master

Hello @Snika ,

the OSPF standard allows to write the OSPF area-id in dotted decimal format like an IP address.

And like an IP address in dotted decimal format you can have formulas for conversion.

So for example

area 1.0.0.0 is not area 1   but it is a huge number  1 * 2^24  = 16,777,216.

Area ids in dotted decimal format are used by other vendors and provide a way to document the address block that is within a non zero area.

For example if address block 172.17.0.0/16 is within an area instead of naming the area 3 we could name it

area 172.17.0.0 making the area id meaning the address block inside it.

Hope to help

Giuseppe

VIP Expert

adding to @Giuseppe Larosa ,  there is a good tool I come across how you can calculate the area with dotted decimal to decimal

https://www.beyondcli.com/ospf-conversion/

*** Rate All Helpful Responses ***

Participant

im tested

solved

5 REPLIES 5

there should not be any difference between 2 ways of doing same thing.

"area 0.0.0.1" means  "area 1"

Regards, ML

Participant

If so, for example, what is area, 1.0.0.0, 1.1.0.0, 1.1.1.1?

Hall of Fame Master

Hello @Snika ,

the OSPF standard allows to write the OSPF area-id in dotted decimal format like an IP address.

And like an IP address in dotted decimal format you can have formulas for conversion.

So for example

area 1.0.0.0 is not area 1   but it is a huge number  1 * 2^24  = 16,777,216.

Area ids in dotted decimal format are used by other vendors and provide a way to document the address block that is within a non zero area.

For example if address block 172.17.0.0/16 is within an area instead of naming the area 3 we could name it

area 172.17.0.0 making the area id meaning the address block inside it.

Hope to help

Giuseppe

Participant

im tested

solved

VIP Expert

adding to @Giuseppe Larosa ,  there is a good tool I come across how you can calculate the area with dotted decimal to decimal

https://www.beyondcli.com/ospf-conversion/

*** Rate All Helpful Responses ***

Create Content to create content