From: Venkataramanaiah.R (vramanaiah@gmail.com)
Date: Sun Nov 20 2005 - 10:56:27 GMT-3
But that effectively means you are enabling OSPF on the R2 i/f towards
R1. You could achieve the same result, by adding this i/f as well,
with 0.0.0.0 wildcard mask. This way, you control exactly which i/fs
run OSPF. A wider wildcard might inadverdently include other i/fs
which might get created due to other tasks in the lab... Just my
thoughts.
-Venkat
On 11/18/05, Peter McCreesh <petermccreesh@gmail.com> wrote:
> There is a potential issue with using the 0.0.0.0 <http://0.0.0.0> wildcard
> in the following scenario:
>
> R1(10.1.1.1 <http://10.1.1.1>)RIP--------------RIP(10.1.1.2<http://10.1.1.2>
> )R2(10.1.2.2
> <http://10.1.2.2>)OSPF-----------------OSPF(10.1.2.3<http://10.1.2.3>)R3-----
> ----[assume
> R3 has another route to R1(10.1.1.1 <http://10.1.1.1>)]
>
> If you use the 0.0.0.0 <http://0.0.0.0> wildcard on R2 and redistribute RIP
> into OSPF, by default OSPF will advertise itself as the next hop for the
> redistributed routes to R3 (nothing to do with the 0.0.0.0
> <http://0.0.0.0>wildcard, just normal) but if you wanted R2 to
> advertise R1(
> 10.1.1.1 <http://10.1.1.1>) as the next hop for the redistributed routes to
> R3, it wouldn't because the wildcard is specific to the interface and not
> the network.
>
> I hope this is explained somewhat clearly!!!!
>
> HTH......Pete
>
>
> On 11/17/05, Leigh Harrison <ccileigh@gmail.com> wrote:
> >
> > Just to throw my hat in the ring:-
> >
> > I ALWAYS specify the interface with a 0.0.0.0 <http://0.0.0.0> wildcard.
> > That way it
> > will not do anything unexpected to me.
> >
> > LH
> >
> > Danny Cox wrote:
> >
> > >>Dave, get out that off way of putting OSPF Interfaces, I learn that they
> > >>could lead us to many errors...
> > >>Be very specific if you need to enable OSPF in certains interfaces..
> > >>
> > >>
> > >
> > >
> > >
> > >> network 172.16.16.100 <http://172.16.16.100> 0.0.0.0 <http://0.0.0.0>area
> 16
> > >>
> > >>
> > >
> > >This is off topic, sorry, but why *not* specify it with a matching
> > >wildcard mask to the interface as Dave did? Surely from a CCIE lab
> > >point of view it doesn't matter so long as the interface ends up
> > >participating in the OSPF ?
> > >
> > >We've actually talked about this at work a bit - is there a consensus
> > >as to which is better other than perhaps you're a bit less likely to
> > >make mistakes with a 0.0.0.0 <http://0.0.0.0> wildcard mask?
> > >
> > >cheers
> > >Danny
> > >
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