From: Peter van Oene (pvo@xxxxxxxxxxxx)
Date: Sun Aug 04 2002 - 11:28:28 GMT-3
At 11:16 PM 8/3/2002 -0400, Hansang Bae wrote:
>At 10:10 PM 8/2/2002 -0400, Peter van Oene wrote:
> >I fully disagree and suggest that single area OSPF networks should NOT
> use area 0.0.0.0 as their area ID. Using a non special identifier
> provides the most flexibility in the future. Futher, there is nothing
> invalid about an OSPF network that doesn't have an area 0 so long as it
> employs only one area.
>
>
>These are pretty academic discussions. If you only have one area, then
>you don't have too many routers so it's no big deal to change the area
>number. If you have more than one area, you *have* to have a backbone
>area, so that solves that problem.
>
>If you merge with another company, why would you want to use an IGP to
>link to routing domains? That's what EGPs are for.
>
>or so it seems to me.
I don't entirely agree. What if you have 200 routers in one area? This is
not entirely uncommon.
On the merger side, keep in mind that both, neither, or one of the
companies may run BGP already. In the first case, there should be a desire
to merge the two AS's in order to unify the routing policy and allow the
most effective and simple use of technologies like MPLS for TE/VPN
applications. In the second case, you'd be inclined to add the non BGP
company to the BGP mesh of the first given it didn't already have its own
AS and for the aforementioned single AS benefits. Moving to a confederated
setup would force downtime and reconfig on all your 200 routers which
wouldn't at all be appealing. In the final case, neither AS running BGP,
you might consider two private AS's, though you'd likely end up with
sub-optimal routing between the two AS's due to the lack of link layer
granularity in BGP metrics and be forced into a confederated setup in the
future should you ever wish public BGP connectivity and your confed
topology may not be entirely optimal as it was put in place for non
performance oriented reasons.
In any event, I would wonder why one would put oneself in this situation in
the first place. Simply take the safe steps to allow for controlled growth
which would include no assigning single area networks the 0.0.0.0 identifier.
>hsb
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