From: Tim (ccie2be@nyc.rr.com)
Date: Mon Sep 12 2005 - 11:08:51 GMT-3
Ryan,
I think the key to success on the lab regarding this topic is understanding
what the different effects of failure of the primary gateway will be on the
hosts.
With the dhcp default-gateway command used to provide multiple gateways, it
is up to the hosts to figure out when the primary gateway is no longer
available and use a secondary gateway. This might require that irdp is also
configured. But, the critical point is this: What happens when the primary
gateway fails depends on the hosts and the failure of the primary gateway
may result in active sessions on the host timing out.
With HRSP, VRRP and GLBP, the failure of the primary gateway and switchover
to a secondary gateway is transparent to hosts on the segment.
As long as you understand this, you should be OK on the lab if you encounter
a task like this. But, of course, if you have any doubt as to what you're
being asked to do, ASK THE PROCTOR. That's what they're there for.
HTH, Tim
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Private Ryan
Sent: Sunday, September 11, 2005 11:00 PM
To: Marvin Greenlee
Cc: ccielab@groupstudy.com
Subject: RE: multiple default-router in DHCP
Thanks.
I used a windows machine for DHCP testing and it can
install several ip in "Default Gateway". When I
shutdown the first IP address, the windows can't use
the second address. don't know how windows hand
multiple ip addresses as default gateway.
Ryan
--- Marvin Greenlee <marvingreenlee@yahoo.com> wrote:
> When multiple addresses are used, it is up to the
> client implementations to determine when each of the
> gateway addresses are unavailable. DHCP just hands
> the addresses out.
>
> - Marvin Greenlee, CCIE #12237
>
> --- Private Ryan <private_ryan2k1@yahoo.com> wrote:
>
> > What is the use of
> > > default-router address [address2 ... address8]
> > in DHCP option?
> >
> > thanks !
> >
> > Ryan
> > --- "Chris Lewis (chrlewis)" <chrlewis@cisco.com>
> > wrote:
> >
> > > VRRP?
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com
> > > [mailto:nobody@groupstudy.com] On Behalf Of
> > > Venkataramanaiah.R
> > > Sent: Sunday, September 11, 2005 8:08 AM
> > > To: Private Ryan
> > > Cc: ccielab@groupstudy.com
> > > Subject: Re: multiple default-router in DHCP
> > >
> > > I faced a similar issue.. I guess what is
> required
> > > here is to configure
> > > IRDP on both the routers, Is there any better
> > > solution to this problem?
> > >
> > > -Venkat
> > >
> > > On 9/11/05, Private Ryan
> > <private_ryan2k1@yahoo.com>
> > > wrote:
> > > >
> > > > Hi,
> > > >
> > > > In dhcp server configuration, I can enter up
> to
> > 8
> > > address for
> > > > default-router. I tested the dhcp using router
> > as
> > > a dhcp client. I
> > > > found that it always use the 1st address as
> > > default gateway. even if I
> > >
> > > > shutdown the 1st address in my network, the
> > client
> > > will never use the
> > > > 2nd address. When "address2 ... address8 "
> > > > will be used ?
> > > >
> > > > Router(dhcp-config)# default-router address
> > > [address2 ... address8]
> > > >
> > > > Another Question
> > > > Configure DHCP for VLAN A subnet and R1 as
> > default
> > > gateway. Use R2 as
> > > > default gateway when R1 is down.
> > > > You are not allowed to use HSRP. Should I use
> > > > "address2 ... address8" for my solution?
> > > >
> > > > i.e. default-router R1 R2
> > > >
> > > > Thanks !
> > > >
> > > >
> > __________________________________________________
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> >
>
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