From: Brian McGahan (bmcgahan@internetworkexpert.com)
Date: Mon Oct 30 2006 - 18:48:30 ART
> If an arp request from 1.1.1.2/24 were seen by a router at 1.1.1.1/24
> and a router at 2.2.2.1/24 on the same segment, would their be any
> special configuration required to prevent 2.2.2.1 from answering?
No extra configuration is needed. The router at 2.2.2.1/24 will
not respond to an ARP from 1.1.1.2 unless Local Area Mobility is
enabled.
Brian McGahan, CCIE #8593 (R&S/SP)
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987 x 705
Outside US: 775-826-4344 x 705
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> -----Original Message-----
> From: Fosket, William [mailto:William.Fosket@compass.net]
> Sent: Monday, October 30, 2006 3:06 PM
> To: Brian McGahan; Venkataramanaiah.R
> Cc: ccielab@groupstudy.com
> Subject: RE: Proxy-Arp with two routers on a segment..
>
> It's more of an issue of where the request is coming from than where
> they are trying to get to, I think. It is more a question about how
arp
> works than how proxy arp works. Though the requests would come from
the
> same segment, they'd be coming from different subnets (if I understood
> correctly).
>
> If an arp request from 1.1.1.2/24 were seen by a router at 1.1.1.1/24
> and a router at 2.2.2.1/24 on the same segment, would their be any
> special configuration required to prevent 2.2.2.1 from answering?
>
> Bill Fosket CCIE #16041
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Brian McGahan
> Sent: Monday, October 30, 2006 1:47 PM
> To: Venkataramanaiah.R
> Cc: ccielab@groupstudy.com
> Subject: RE: Proxy-Arp with two routers on a segment..
>
> The ARP request will always come in from a host on a directly
> connected segment. If the router has a route to the ARP's destination
> and proxy-arp is enabled on the connected link that the ARP was
received
> the router will reply with its own MAC address. The destination does
> not have to be connected, it just has to be in the routing table.
>
> Diagram out your topology and let me know exactly what you are
> trying to accomplish and I can give you a better recommendation.
>
>
> HTH,
>
> Brian McGahan, CCIE #8593 (R&S/SP)
> bmcgahan@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987 x 705
> Outside US: 775-826-4344 x 705
> 24/7 Support: http://forum.internetworkexpert.com
> Live Chat: http://www.internetworkexpert.com/chat/
>
>
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of
> > Venkataramanaiah.R
> > Sent: Monday, October 30, 2006 10:59 AM
> > To: Brian McGahan
> > Cc: ccielab@groupstudy.com
> > Subject: Re: Proxy-Arp with two routers on a segment..
> >
> > Brian, Moreover, you suggestion will apply only if i am proxy arping
B
> > from A and vice versa.. But when i arp any other subnets, both
routers
> > will have these routers..
> >
> > In any case, i think bill's understanding with this issue is
correct.
> > Routers seem to responding only to the connect hosts. (They verify
> > source addresses before responding with MAC). However, in our case,
> > our legacy hosts, which uses same NIC for both subnets, never uses
> > second subnet to ask for MAC. So always R1 responds..
> >
> >
> >
> > On 10/30/06, Venkataramanaiah. R <vramanaiah@gmail.com> wrote:
> > > Brian, I like your advise, but i cannot do that, i want this
> > > intercommunication to around via both routers..
> > >
> > > It is a strange topology that we are trying to build upon here,
with
> > > legacy telcom hosts. So bear with me for that ;-)
> > >
> > > thanks
> > >
> > >
> > > On 10/30/06, Brian McGahan <bmcgahan@internetworkexpert.com>
wrote:
> > > > You will only reply with proxy-arp if you have a route to the
> > requested
> > > > host's subnet. Remove router 1's route to subnet 2 and remove
> router
> > > > 2's route to subnet 1 and you will see the desired behavior.
> > > >
> > > >
> > > > HTH,
> > > >
> > > > Brian McGahan, CCIE #8593 (R&S/SP)
> > > > bmcgahan@internetworkexpert.com
> > > >
> > > > Internetwork Expert, Inc.
> > > > http://www.InternetworkExpert.com
> > > > Toll Free: 877-224-8987 x 705
> > > > Outside US: 775-826-4344 x 705
> > > > 24/7 Support: http://forum.internetworkexpert.com
> > > > Live Chat: http://www.internetworkexpert.com/chat/
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> Behalf
> > > > Of
> > > > > Venkataramanaiah.R
> > > > > Sent: Saturday, October 28, 2006 1:09 PM
> > > > > To: ccielab@groupstudy.com
> > > > > Subject: Proxy-Arp with two routers on a segment..
> > > > >
> > > > > I have a requirement where there will be two routers on the
same
> > > > > segment supporting two different subnets... The segments have
> hosts
> > > > > belonging to both these subnets..
> > > > >
> > > > > I want to enforce the following..
> > > > >
> > > > > Router 1 must respond to proxy-arp request only from hosts
> belonging
> > > > > to Subnet 1.
> > > > >
> > > > > Router 2 must respond to proxy-arp request only from hosts
> belonging
> > > > > to Subnet 2.
> > > > >
> > > > > Is there a way out..? I cant think of any way to achieve
this,
> so
> > > > > thought i will ask the experts :-)
> > > > >
> > > > >
> > > > > Regards
> > > > > -Venkat
> > > > >
> > > > >
> > > >
> >
>
This archive was generated by hypermail 2.1.4 : Wed Nov 01 2006 - 07:29:07 ART