Re: Question: Why use network X.X.X.X 0.0.0.0 area 0?

Like the others have said, mainly it is to make things as specific as possible so you do not inadvertantly advertise more than you bargained for
------Original Message------
From: Marko Milivojevic
Sender: nobody_at_groupstudy.com
To: Anthony Sequeira
Cc: Justin Mitchell
Cc: CCIE Groupstudy
Subject: Re: Question: Why use network X.X.X.X 0.0.0.0 area 0?
Sent: Oct 18, 2009 4:14 PM

On Sun, Oct 18, 2009 at 20:08, Anthony Sequeira <asequeira_at_ine.com> wrote:
> Most of us do this to not accidentally bring another interface into the OSPF
> domain.
>
> The "equivalent" configuration approaches you will often see for the other
> IGPs are:
>
> router eigrp 100
> network 172.16.1.1 0.0.0.0
>
> and
>
> router rip
> version 2
> passive-interface default
> network 172.16.0.0
> no passive-interface fa0/0

And with OSPF:

int A/B
 ip ospf X area Z
!

IS-IS has always been like that - enabled on interface only:

int A/B
 ip router isis X
!

In past few months, I tend to prefer this approach. It's more
streamlined and logical, but it's hard to unlearn certain things (like
network command).

--
Marko
CCIE #18427 (SP)
My network blog: http://cisco.markom.info/
Blogs and organic groups at http://www.ccie.net