From: Rick Burts (burts@xxxxxxxxxxxxxx)
Date: Fri Apr 27 2001 - 14:54:59 GMT-3
Chuck
I think Atif nailed this one.
To explore your perspective which was that the decision was based on
the running protocol: what does happen when a router runs both RIP
and OSPF ?
I believe that the explanation is correct that the routing protocol
builds the routing table. The routing protoco does not make a
forwarding decision. That is done by a separate process and that
process is what is affected by ip classless) or not).
Rick
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On Fri, 27 Apr 2001, Chuck Larrieu wrote:
> Hhhmmmmm....... I'm not sure this is exactly correct, but I am certainly
> open to a good explanation, as I am a bit unsure myself.
>
> But I believe that the router acts based on the routing protocol in
> question. If the routing protocol is rooted in the classful world (e.g.
> RIPv1 or IGRP) then decisions are based on classful behaviour. Otherwise
> (OSPF, BGP) the router will behave according to classless requirements.
>
> Has anyone done a specific experiment to test this?
>
> Chuck
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Atif
> Awan
> Sent: Friday, April 27, 2001 2:57 PM
> To: radhaccie@hotmail.com; ccielab@groupstudy.com
> Subject: Re: ip classless
>
> This command changes the router's lookup algorithm. No doubt OSPF is a
> classless protocol but it only provides the router with the routes, it does
> not in any way affect the way a router determines how to forward packets
>
> that is using the classful or the classless algorithm ).
>
> >From: "radha rani" <radhaccie@hotmail.com>
> >Reply-To: "radha rani" <radhaccie@hotmail.com>
> >To: ccielab@groupstudy.com
> >Subject: ip classless
> >Date: Fri, 27 Apr 2001 10:00:06 -0400
> >
> >I have a question re: ip classless. My understanding is that if there is
> >no
> >specific route for a subnet in the routing table, this command allows the
> >router to forward packets to unknown destinations using the default route.
> >This being the case when the destination is a subnet of a network which is
> >known to the router.
> >
> >My question is : since OSPF is a classless protocol, why do I need this
> >command to have the router forward packets using the default route. I see
> >this all the time where the router will not utilize the default route until
> >this command is added.
> >
> >I can unserstand needing it with IGRP/RIP but why with OSPF?
> >
> >Can someone expalin. Thanks so much.
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