Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

v.j
New Member

ospf !

Is it compulsory to have area 0 , even when the design has only one area to be created.

Can we define different areas on primary and secondary address of the same interface.

Tanx

3 REPLIES
New Member

Re: ospf !

Yes, if the design is for a single OSPF area, it must be defined as Area 0. IT is mandatory that you have an Area 0.

I beleive you *probably* define more than one area on an interface, but I wouldn't do it. I also can't think of a reason why you would want to.

You should read up on OSPF, a good start would be to check out Cisco's OSPF Design Guide at:

http://www.cisco.com/warp/public/104/1.html

New Member

Re: ospf !

Not using area 0 isn't mandatory as such, but you won't be able to have any additional areas without it. You may also run into issues with other vendors' (servers included) implementations of OSPF if there is no area 0.

You *can* place secondary interfaces in other areas, but they won't form adjacencies. They will be advertised as stubs. You'll also have an issue if another vendor's routers' can support secondary interface adjacencies since the primary interface will think that the peer is sending bad LSAs.

Mick.

v.j
New Member

Re: ospf !

Hi all thanx! I had that doubt on area 0 becoz i read from a cisco press book saying area 0 isnt mandatory which was published in 1998.

Tanx again.

103
Views
0
Helpful
3
Replies