From: Scott Morris (swm@emanon.com)
Date: Tue Jan 04 2005 - 20:58:40 GMT-3
Brian is absolutely right, if you think too much, you'll just go nuts. :)
(Speaking from experience there, I'm sure we all are! (grin))
With two default routers, you'll rely on the hosts inability to reach one
gateway before failing over. Hosts' ARP has a two-minute timeout by
default, so that's not exactly an efficient way to go!
My thinking process would say that it would depend on exactly what section
that scenario appeared in. If your point section title was something about
DHCP services, then I would agree that multiple dhcp default routers would
work nicely. If it was a separate point section about router redundancy
(note router redundancy, not hosts' ability to choose multiple paths) then I
would opt with HSRP, VRRP or some other flavor du jour.
The exams are written in a semi-logical format. It may not always seem that
way, but pay attention to ALL words and structure!
HTH,
Scott Morris, MCSE, CCDP, CCIE4 (R&S/ISP-Dial/Security/Service Provider)
#4713, JNCIP, CCNA-WAN Switching, CCSP, Cable Communications Specialist, IP
Telephony Support Specialist, IP Telephony Design Specialist, CISSP
CCSI #21903
swm@emanon.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Brian Dennis
Sent: Tuesday, January 04, 2005 6:08 PM
To: ccie2be; ccielab@groupstudy.com
Subject: RE: dhcp default-router vs hsrp [bcc][faked-from]
Tim,
If I was the proctor and you asked me that question I would just
tell you to choose the best solution because there is no clarity needed in
that task. Here's why. The task didn't say anything about what type of
hosts are in the VLAN so you can't be certain that they will accept two
default gateways via DHCP. This means that the ONLY solution you can be
certain will work for all possible hosts would be HSRP.
Remember to choose the best solution with the information given.
Don't try to outthink the question and don't add a bunch of "what if's"
to the question. You'll drive yourself crazy thinking of solutions if you
do.
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
ccie2be
Sent: Tuesday, January 04, 2005 1:51 PM
To: marvin greenlee; ccielab@groupstudy.com
Subject: Re: dhcp default-router vs hsrp [bcc][faked-from]
Hi Marvin,
Thanks for your response.
Given the difference in funtionality between these 2 methods, is it your
opinion that in the lab,
if all that is specified is the need for redundancy, we should be bias
towards using hsrp?
Thanks again, Tim
----- Original Message -----
From: "marvin greenlee" <marvin@ccbootcamp.com>
To: "'ccie2be'" <ccie2be@nyc.rr.com>; <ccielab@groupstudy.com>
Sent: Tuesday, January 04, 2005 4:45 PM
Subject: RE: dhcp default-router vs hsrp [bcc][faked-from]
> With DHCP, if multiple default routers are provided, it is up to the
host
to
> determine the availability of the gateway, and, if necessary, switch
to
the
> next default. Depending on the hosts' functionality, it may not
properly
> determine the availability.
>
> By configuring HSRP, you can remove the responsibility for determining
> availability from the host, and let the routers do the work.
>
> - Marvin Greenlee, CCIE#12237, CCSI# 30483
> Network Learning Inc
> marvin@ccbootcamp.com
> www.ccbootcamp.com (Cisco Training)
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> ccie2be
> Sent: Tuesday, January 04, 2005 1:22 PM
> To: Group Study
> Subject: dhcp default-router vs hsrp [bcc][faked-from]
> Importance: Low
>
> Hi guys,
>
> In IE lab 13, task 12.3, the requirement was to provide redundancy for
dhcp
> clients on a given lan segment -
>
> "The default gateway for these hosts should be R6. If R6 is down, R3
should
> be the default gateway."
>
> My immediate thought was to use the dhcp command, default-router <R6's
addr>
> <R3's addr>.
>
> But, the SG shows HSRP being configured instead.
>
> My question is in the real lab, if there's a similar requirement,
would
> either
> approach be acceptable?
>
> I acknowledge that using hsrp is probably better for a couple of
reasons -
> faster switchover, works with all hosts - but
>
> if I used the default-router command, is that wrong?
>
> TIA, Tim
>
>
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