Re: [dhcwg] DHCP server deleting the IP-MAC binding entry

girish gupta <girishkg@gmail.com> Fri, 09 October 2009 05:03 UTC

Return-Path: <girishkg@gmail.com>
X-Original-To: dhcwg@core3.amsl.com
Delivered-To: dhcwg@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 2D14D3A6823 for <dhcwg@core3.amsl.com>; Thu, 8 Oct 2009 22:03:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.534
X-Spam-Level:
X-Spam-Status: No, score=-2.534 tagged_above=-999 required=5 tests=[AWL=0.065, BAYES_00=-2.599]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OS7Vxr0qf9Iz for <dhcwg@core3.amsl.com>; Thu, 8 Oct 2009 22:03:12 -0700 (PDT)
Received: from mail-px0-f204.google.com (mail-px0-f204.google.com [209.85.216.204]) by core3.amsl.com (Postfix) with ESMTP id 4361D3A67C2 for <dhcwg@ietf.org>; Thu, 8 Oct 2009 22:03:12 -0700 (PDT)
Received: by pxi42 with SMTP id 42so6392845pxi.5 for <dhcwg@ietf.org>; Thu, 08 Oct 2009 22:04:53 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=ow88FSdkcxMJXYxpdByUid1HUU0l9RDbjvi1irW9Ka0=; b=cc+VwR1uwB25ucxhKU5B+FMqfXRH1gz04ShwR0mhbFXexVCVlJiL45mx083JHqi+os CD+qZxZWl00EfLAsUcQcE4srIhPnP4bIA23d666P0EBahTl7vzSJS+XfKZKS/sySZ4vp NE2QXIz1D9gLvW9no2smMFEk+Y0QjQPv40hF0=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=CO7detBzjYdBaL5kF7vTRK5F2FQylE9rkJ/Mho519Rqq1WKX7PbcDKUA4ZbjzlgWGO PcdKC5jppEMzTXDVCtFI5SUxvh9qLHtomm/fyIZegiEbVauHQx1PpXtAz14Ktqfy9+pe Z2Gufh9VKLwKMGFxywZotsuW8L7G0/T2qhfR4=
MIME-Version: 1.0
Received: by 10.114.44.8 with SMTP id r8mr3275473war.80.1255064693103; Thu, 08 Oct 2009 22:04:53 -0700 (PDT)
In-Reply-To: <aea859fb0910080213o6956321vf375982bfc46c5d8@mail.gmail.com>
References: <aea859fb0910080146k6e9852aavaf936e85d366d6d8@mail.gmail.com> <890889.84417.qm@web95314.mail.in2.yahoo.com> <aea859fb0910080213o6956321vf375982bfc46c5d8@mail.gmail.com>
Date: Fri, 09 Oct 2009 10:34:53 +0530
Message-ID: <aea859fb0910082204i48d13e9u44d97b08fc0c9bbb@mail.gmail.com>
From: girish gupta <girishkg@gmail.com>
To: dhcwg@ietf.org, GAURAV HALWASIA <gauravh278@yahoo.co.in>
Content-Type: text/plain; charset="ISO-8859-1"
Subject: Re: [dhcwg] DHCP server deleting the IP-MAC binding entry
X-BeenThere: dhcwg@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <dhcwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dhcwg>
List-Post: <mailto:dhcwg@ietf.org>
List-Help: <mailto:dhcwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 09 Oct 2009 05:03:13 -0000

Hi Gaurav,

What I proposed is the quick convergence of DHCP database on Clients
and DHCP Snooping switches to be consistence with DHCP Server
database.
Existing mechanism do not provide any such mechanisms. Another point
is that since the binding entry is being deleted from DHCP server,
DHCP server can offer the same IP address to some other new clients
and client SHOULD have been implemented for sending ARP request for
detecting the already assigned IP addresses else it will add to more
confusion....

Thanks,
Girish



On Thu, Oct 8, 2009 at 2:32 PM, GAURAV HALWASIA <gauravh278@yahoo.co.in> wrote:
> Hi Girish,
>
> As per protocol DHCP Server will not send any DHCP message to client in case
> adminitrator manually clears the DHCP bindings.
>
> DHCP clients will get re-initialized automatically after it's renew requests
> will not get responded. It might not be great idea to force the client to
> release the IP address before the lease time gets expired.
>
>
> Regards,
> Gaurav Halwasia
>
> ________________________________
> From: girish gupta <girishkg@gmail.com>
> To: dhcwg@ietf.org
> Sent: Thu, 8 October, 2009 2:16:28 PM
> Subject: [dhcwg] DHCP server deleting the IP-MAC binding entry
>
> Hello Experts,
>
> I read RFC 2131 and have the following query -
>
> If the administrator manually deletes the dhcp IP-MAC binding entry
> from the DHCP server database, is there any DHCP message generated for
> it? I think it is not generated. Please let me know if we are missing
> anything. Will it not be a good idea to generate a new DHCP message
> which can flush the state of DHCP clients/DHCP Snooping switches and
> re-initialize their state machines?
>
> Please let me know your thoughts.
>
> Thanks,
> Girish
> _______________________________________________
> dhcwg mailing list
> dhcwg@ietf.org
> https://www.ietf.org/mailman/listinfo/dhcwg
>
> ________________________________
> Keep up with people you care about with Yahoo! India Mail. Learn how.