Re: DHCP Server - Default-router List

i think you would need to look into the operation of each client type you
set this up for, for example on the Microsoft sight you can see their client
will accept multiple gateways, now what it actually does with that
information who knows?

"Default Router (3): The router option specifies a list of IP addresses for
routers on the client's subnet. Routers should be listed in order of
preference. The code for the router option is 3. The minimum length for the
router option is 4 octets, and the length MUST always be a multiple of 4."

http://support.microsoft.com/kb/121005/EN-US/

as for using a Cisco router as a dhcp client, not sure it will accept more
than one default router, and just assume that would be the first one in the
list, would have to research the client options on the Cisco side

i am sure linux, and other OSes behave all different or follow some loose
interpretation of the RFC for "client dhcp operations" whatever that is??

--
Garry L. Baker
"There is no 'patch' for stupidity." - www.sqlsecurity.com
On Fri, Nov 19, 2010 at 3:15 PM, Tom Kacprzynski <tom.kac_at_gmail.com> wrote:
> Brain,
> Thank you for your response. I'm trying to figure out what is the feature
> for in the DHCP server. How could a DHCP server give out up to 8 IP
> addresses that can be used as a default route. Yes HSRP would work great to
> provide first hop redundancy, but why would cisco provide the option of
> giving out 8 IP addresses if the client will take the first address. As far
> as i could see, yes it does take the first one, even if that first one is
> not reachable, so no arp or icmp ping for it from the client.
>
>
> Regards,
>
> Tom
>
>
>
>
> On Fri, Nov 19, 2010 at 3:09 PM, Mahaffey, Brian <bmahaffey_at_pelco.com
> >wrote:
>
> > Have you looked into HSRP and just giving the clients one default
> > router? I would assume the client would accept the first one it
> > receives, but I am just guessing.
> >
> > -----Original Message-----
> > From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> > Tom Kacprzynski
> > Sent: Friday, November 19, 2010 12:50 PM
> > To: Cisco certification
> > Subject: Re: DHCP Server - Default-router List
> >
> > Anyone, please? I'm stuck.
> >
> > thanks
> >
> >
> > On Thu, Nov 18, 2010 at 7:21 PM, Tom Kacprzynski <tom.kac_at_gmail.com>
> > wrote:
> >
> > > Hello,
> > > Just a quick question regarding IOS DHCP server and the default-router
> > > list.
> > >
> > > If I have a pool that specifies multiple default routers, but what I
> > don't
> > > understand is how does the client pick one of the other?
> > >
> > > Sample config below.
> > >
> > > Rack1R1#sh run | s pool
> > > ip dhcp pool TEST
> > >    network 155.1.146.0 255.255.255.0
> > >    default-router 155.1.146.10 155.1.146.1
> > >    dns-server 155.1.146.1
> > >
> > > Based on this the client takes the first IP address for default
> > router,
> > > even if that router is not reachable it does not failover.
> > >
> > > Does anyone know how you could use the two IP addresses and how does
> > the
> > > client switch between them?
> > >
> > > Thank you,
> > >
> > > Tom Kacprzynski
> >
> >
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