From: fangbo (fangbo@gmail.com)
Date: Tue Oct 31 2006 - 01:33:08 ART
Hi there,
I guess the host will send arp request to broadcast( FFFFFFFFFFFF), so every
routers on same segment will get the request and send arp reply out if he
know the route to destination.
Is this right?
Thanks and regards,
tim
-----SJ<~T-<~-----
7"<~HK: nobody@groupstudy.com [mailto:nobody@groupstudy.com] 4z1m Brian
McGahan
7"KMJ1<d: 2006Dj10TB31HU 5:49
JU<~HK: Fosket, William; Venkataramanaiah.R
3-KM: ccielab@groupstudy.com
VwLb: RE: Proxy-Arp with two routers on a segment..
> 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
24/7 Support: http://forum.internetworkexpert.com
Live Chat: http://www.internetworkexpert.com/chat/
> -----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