RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-timeconfig-02.txt
"Vijayabhaskar A K" <vijayak@india.hp.com> Tue, 21 October 2003 16:33 UTC
Received: from optimus.ietf.org (ietf.org [132.151.1.19] (may be forged)) by ietf.org (8.9.1a/8.9.1a) with ESMTP id MAA25513; Tue, 21 Oct 2003 12:33:24 -0400 (EDT)
Received: from localhost.localdomain ([127.0.0.1] helo=www1.ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 1ABzRN-0001mK-Oa; Tue, 21 Oct 2003 12:33:01 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 1ABzQO-0001PM-T2 for dhcwg@optimus.ietf.org; Tue, 21 Oct 2003 12:32:01 -0400
Received: from ietf-mx (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id MAA25456 for <dhcwg@ietf.org>; Tue, 21 Oct 2003 12:31:49 -0400 (EDT)
Received: from ietf-mx ([132.151.6.1]) by ietf-mx with esmtp (Exim 4.12) id 1ABzQN-0005j2-00 for dhcwg@ietf.org; Tue, 21 Oct 2003 12:31:59 -0400
Received: from palrel13.hp.com ([156.153.255.238]) by ietf-mx with esmtp (Exim 4.12) id 1ABzQL-0005iz-00 for dhcwg@ietf.org; Tue, 21 Oct 2003 12:31:58 -0400
Received: from iconsrv5.india.hp.com (iconsrv5.india.hp.com [15.42.229.13]) by palrel13.hp.com (Postfix) with ESMTP id C7B7B1C0146E; Tue, 21 Oct 2003 09:31:53 -0700 (PDT)
Received: from nt23056 (nt23056.india.hp.com [15.42.230.56]) by iconsrv5.india.hp.com (8.9.3 (PHNE_28810)/8.9.3 SMKit7.02) with ESMTP id WAA21991; Tue, 21 Oct 2003 22:00:41 +0530 (IST)
From: Vijayabhaskar A K <vijayak@india.hp.com>
To: 'Ralph Droms' <rdroms@cisco.com>
Cc: Margaret.Wasserman@nokia.com, narten@us.ibm.com, dhcwg@ietf.org
Subject: RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-timeconfig-02.txt
Date: Tue, 21 Oct 2003 22:01:43 +0530
Message-ID: <004a01c397f0$d04824c0$38e62a0f@nt23056>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="----=_NextPart_000_004B_01C3981E.EA0060C0"
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook, Build 10.0.4024
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165
Importance: Normal
In-Reply-To: <4.3.2.7.2.20031021121740.048735d0@flask.cisco.com>
Sender: dhcwg-admin@ietf.org
Errors-To: dhcwg-admin@ietf.org
X-BeenThere: dhcwg@ietf.org
X-Mailman-Version: 2.0.12
Precedence: bulk
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=unsubscribe>
List-Id: <dhcwg.ietf.org>
List-Post: <mailto:dhcwg@ietf.org>
List-Help: <mailto:dhcwg-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=subscribe>
Ralph, I have submitted the draft-ietf-dhc-dhcpv6-opt-timeconfig-03.txt last week. Still, it is not published, though I submitted nisconfig-03 and timeconfig-03 together. Shall I proceed with the splitting up of the drafts (or) shall I wait for timeconfig-03 to get published? I am attaching the draft-ietf-dhc-dhcpv6-opt-timeconfig-03.txt along with this mail. ~ Vijay -----Original Message----- From: dhcwg-admin@ietf.org [mailto:dhcwg-admin@ietf.org] On Behalf Of Ralph Droms Sent: Tuesday, October 21, 2003 9:50 PM To: vijayak@india.hp.com Cc: Margaret.Wasserman@nokia.com; narten@us.ibm.com; dhcwg@ietf.org Subject: RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-timeconfig-02.txt Seems to me we are closer to consensus on publishing the option for (S)NTP servers than we are for the timezone configuration option. Vijay, I suggest you split your current draft into two drafts, one for the (S)NTP servers option (call it draft-ietf-dhc-dhcpv6-opt-timeconfig-03.txt if you can publish it this week) and a new draft for the timezone option. With two documents, we can let each option proceed at its own pace... - Ralph At 12:59 AM 10/7/2003 +0530, Vijayabhaskar A K wrote: >Hi Margaret > >Thanks for your very quick reply. My reply inline > >~ Vijay > > > > > Hi Vijay, > > > > Thanks for your response. > > > > > > General question on this document: We recently deprecated the > > > > option code allocation for the IPv4 version of this > > option. Why do > > > > we think that there is a greater need for this in IPv4 > > than in IPv6? > > > > Has anyone implemented these options? > > > > > > NTP version 4.0 available in www.ntp.org supports IPv6. Most of > > > the vendors provide this version and support NTP on IPv6. So, > > it is really > > > needed. > > > > Your response answers my concern about whether or not NTP is > > available for IPv6, but it doesn't answer my larger concern. > > > > We just deprecated the corresponding configuration options for IPv4, > > because they weren't implemented. Do we have some reason to believe > > that people will implement this option for DHCPv6 when no one > > implemented the same option for IPv4? If so, why? > >One of the two options specified in the draft has been already >standardized for IPv4. Refer RFC 2132, option code : 42, Network Time >Protocol Servers Option. > >There is an option called "Time offset" (option code: 2) defined in RFC >2132. But, it could not convey enough information like day light >savings. Only to provide more information about the timezone, the >draft for "POSIX time zone option for DHCPv4" was written. Meanwhile, >There were few implementations providing this support in the vendor >specific options. One such example is Solaris's >"SUNW.posix-timezone-string" option. Hence, certainly there are few >users. Unfortunately, this draft was not advanced and got expired. As >most of the platforms provided this option in the form of vendor >specific options, nobody really bothered to restart the work and >advance it to the standard. Moreover, I could see alteast 2 >implementation of DHCPv6, which have the support for POSIX time zone >option. (1) HPUX (2) KAME FreeBSD. What I am trying to say is, >Certainly keeping this as an vendor specific option may cause issues >while switching between the servers. Since, this option is used as >vendor specific option in few implementations of DHCPv4 and there are >implementations of DHCPv6 which support this option, its better to >standardize it. > > > > > > > It is also my understand that we haven't (yet) specified how NTP > > > > would run over IPv6, so this option may be premature. > > > > > > Since, there is actually no protocol changes are needed in > > > existing RFC for NTP, there is no specification for NTP on > > IPv6. Its > > > just like another application migration to IPv6. But, IPv6 > > version of > > > NTP are available in various platforms. I don't think this > > option is > > > a premature one. > > > > Actually, there are several IPv4 dependencies in the NTP > > specification, as document in: > > > > http://www.ietf.org/internet-drafts/draft-ietf-v6ops-ipv4surve > > y-apps-02.txt > > > > The folks who have implemented NTP for IPv6 must have worked around > > those dependencies, but I don't believe that their changes have been > > document in an IETF specification (yet). > >The RFC it refers is version 3 of the SNTP protocol. The next version >deals with IPv6 also. > > D. Mills. Simple Network Time Protocol (SNTP) Version 4 for > IPv4, IPv6 and OSI. Request for Comments (Informational) 2030, > Internet Engineering Task Force, October 1996. > > > > > > > What is the reason for specifying a timezone format in this > > > > document, instead of relying completely on another establish > > > > standard for timezone representation? > > > > > > This flexibility is provided to help the vendors to use some other > > > vendor specific database for timezone information. This is > > needed, if > > > they feel that their databases can convey more information > > than POSIX > > > time string. > > [...] > > > > What is a "timezone database"? Is this a standard concept, or > > > > something you are assuming will be specific to each host? If the > > > > latter, why do we need this flexibility? > > > > > > Its not a standard concept. Its something specific to the > > OS. For the > > > last question, you refer the prev answer. > > > > How do you maintain interoperability between the DHCP server and > > clients from multiple vendors, if the server may return the timezone > > in an OS-proprietary format? > >Its basically through vendor-options/class ids. Based on the class-ids >the server can provide different information for the same entity to the >different clients. This is the conventional methodology done from >DHCPv4 onwards. > > > You mentioned > > earlier that this timezone information is set on a per-subnet basis, > > with the assumption that all clients on the same subnet are in the > > same timezone. Do you also assume that all clients on the same > > subnet are running the same OS? > >No, certainly not. There can be clients running different OS. But, they >will be differentiated by the server. > > > > > > > > To avoid attacks through these options, the DHCP client > > SHOULD use > > > > > authenticated DHCP (see section "Authentication of DHCP > > messages" > > > > > in the DHCPv6 specification [1]). > > > > > > > > Why only a "SHOULD"? Given the critical nature of time > > information > > > > to some security protocols, I would prefer a statement that this > > > > option MUST only be used when the DHCP messages are > > authenticated. > > > > Is there a reason not to say that? > > > > > > As such authentication is not mandatory in the DHCPv6 > > > specification (RFC 3315) except for reconfiguration. That's the > > > reason why "MUST" is not used here. > > > > True, although we could require that DHCP security be implemented > > and used whenever certain sensitive options are in use... I'm not > > sure what sort of policy has been used for deciding this in the > > past, though. > > > > > > > [2] D. Mills. Simple Network Time Protocol (SNTP) Version 4 > > > > > for IPv4, IPv6 and OSI. Request for Comments > > > > > (Informational) 2030, Internet Engineering Task Force, October > > > > > 1996. > > > > > > > > This should be a reference to NTP, not to SNTP. > > > > > > Basically, the NTP servers I am referring are SNTP servers. I > > > believe, I could change the "NTP server option" to "SNTP server > > > option". > > > > If that is more accurate, then I think it would make sense to make > > that change. > > > > > > _______________________________________________ > > dhcwg mailing list > > dhcwg@ietf.org > > https://www1.ietf.org/mailman/listinfo/dhcwg > > _______________________________________________ dhcwg mailing list dhcwg@ietf.org https://www1.ietf.org/mailman/listinfo/dhcwg
- [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-time… Margaret Wasserman
- Re: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-… Vijayabhaskar A K
- RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-… Margaret.Wasserman
- RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-… Vijayabhaskar A K
- RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-… Ralph Droms
- RE: [dhcwg] AD Review: draft-ietf-dhc-dhcpv6-opt-… Vijayabhaskar A K