RE: Can you have OSPF without area 0 at all?

From: mdye@bevillcntr.org
Date: Mon Feb 17 2003 - 17:23:13 GMT-3


I agree with Joe. OSPF has full knowledge of Area 0 being the backbone. All
OSPF implementations must have an area 0.

The current RFC for OSPF (2328) says:
  " 3.1. The backbone of the Autonomous System

        The OSPF backbone is the special OSPF Area 0 (often written as
        Area 0.0.0.0, since OSPF Area ID's are typically formatted as IP
        addresses). The OSPF backbone always contains all area border
        routers. The backbone is responsible for distributing routing
        information between non-backbone areas. The backbone must be
        contiguous. However, it need not be physically contiguous;
        backbone connectivity can be established/maintained through the
        configuration of virtual links.
"

Mark Dye

At 02:34 PM 2/17/03 -0500, Joe wrote:
>Please send us the link you refer to. I have to say that this is simply
>not true. You will ONLY send routes from your area, whatever it may be,
>into area 0, the backbone, so you can't just arbitrarily designate any
>area as the backbone. It MUST be area 0.
>
>Joe
>
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>Mark Miller
>Sent: Friday, February 14, 2003 6:15 PM
>To: Sam Munzani; ccielab@groupstudy.com
>Cc: cciesecurity@yahoogroups.com
>Subject: Re: Can you have OSPF without area 0 at all?
>
>
>The routing process in ospf has no concept that "area 0" is the backbone
>area. You can make it any number you want. I remember reading
>something on this. I'll try to dig it up and send you a link.
>
>Mark Miller
>
>
>----- Original Message -----
>From: "Sam Munzani" <sam@munzani.com>
>To: <ccielab@groupstudy.com>
>Cc: <cciesecurity@yahoogroups.com>
>Sent: Friday, February 14, 2003 12:56 PM
>Subject: Can you have OSPF without area 0 at all?
>
>
>> Team,
>>
>> I came across an interesting finding. I want to take everybody's
>> opinion
>on this before putting anything in production. We are building an OSPF
>network that will eventually merge with company's main OSPF backbone
>network. The core group has assigned us ospf area number 555.
>>
>> When I configure all my routers with OSPF area 555(with no area 0 at
>> all),
>it seems to be building up routing table. I always thought OSPF needs
>area 0 to function. Will this work of we add a non cisco device with
>area 555 configuration?
>>
>> What is the catch 22 in this configuration? I have started reading
>> OSPF
>RFC to figure out all technical details.
>>
>> Thanks,
>> Sam Munzani



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