From: Randy Feliz (rjfeliz@xxxxxxxxx)
Date: Fri Apr 27 2001 - 22:34:17 GMT-3
Daneyon,
first of all the best way to verify this correct or
not is to test it in your lab
by default the router will do a classfull lookup...to
test it turn off ip classless..then try to get to a
network that your router is unaware of( you will see
that ever if you have a default route you will not be
able to get to this network) if you debug ip packet
you should see that this packet is unroutable
then turn on ip classless and see if you can get to
the network
note the network that you are trying to reach should
not be a subnet of any network that is connected to
your router
--- daneyon hansen <daneyonhansen@hotmail.com> wrote:
> I believe your understanding of ip classless is a
> little off. By
> default, a router will make IP forwarding decisions
> based on the first
> few high ordered bits of the first octect in the
> destination address
> within the IP header. ie...01 class A, 10 class B
> and 110 class C. By
> turning on IP classless, your telling the router not
> to make forwarding
> decisions based on the first few bits of the
> destination address. Your
> telling the router to make the longest match when
> compaing the
> destination address of the IP packet to the routing
> table. So it really
> has nothing to do with default routing, IP classless
> or no IP classless
> the router will still route to it's default.
>
>
>
> Daneyon
>
> >From: "radha rani" >Reply-To: "radha rani" >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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