Re: [OSPF] Stephen Farrell's No Objection on draft-ietf-ospf-te-metric-extensions-09: (with COMMENT)
Stephen Farrell <stephen.farrell@cs.tcd.ie> Sun, 04 January 2015 13:56 UTC
Return-Path: <stephen.farrell@cs.tcd.ie>
X-Original-To: ospf@ietfa.amsl.com
Delivered-To: ospf@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D5F941A88B2; Sun, 4 Jan 2015 05:56:10 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.91
X-Spam-Level:
X-Spam-Status: No, score=-1.91 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, T_RP_MATCHES_RCVD=-0.01] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id J_Ch84vPyucF; Sun, 4 Jan 2015 05:56:08 -0800 (PST)
Received: from mercury.scss.tcd.ie (mercury.scss.tcd.ie [134.226.56.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 320C71A88B1; Sun, 4 Jan 2015 05:56:08 -0800 (PST)
Received: from localhost (localhost [127.0.0.1]) by mercury.scss.tcd.ie (Postfix) with ESMTP id 5E956BEA4; Sun, 4 Jan 2015 13:56:05 +0000 (GMT)
X-Virus-Scanned: Debian amavisd-new at scss.tcd.ie
Received: from mercury.scss.tcd.ie ([127.0.0.1]) by localhost (mercury.scss.tcd.ie [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id D9eo9vgz-47h; Sun, 4 Jan 2015 13:56:04 +0000 (GMT)
Received: from [10.87.48.73] (unknown [86.46.27.187]) by mercury.scss.tcd.ie (Postfix) with ESMTPSA id B672FBEA0; Sun, 4 Jan 2015 13:56:00 +0000 (GMT)
Message-ID: <54A9466E.6030309@cs.tcd.ie>
Date: Sun, 04 Jan 2015 13:55:58 +0000
From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0
MIME-Version: 1.0
To: adrian@olddog.co.uk, 'The IESG' <iesg@ietf.org>
References: <20150104020718.29256.7059.idtracker@ietfa.amsl.com> <00d301d02802$60ed8990$22c89cb0$@olddog.co.uk>
In-Reply-To: <00d301d02802$60ed8990$22c89cb0$@olddog.co.uk>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Archived-At: http://mailarchive.ietf.org/arch/msg/ospf/DyYECYKFzI13W8uRV1ZFFM2c8BM
Cc: ospf@ietf.org, ospf-chairs@tools.ietf.org, draft-ietf-ospf-te-metric-extensions.all@tools.ietf.org
Subject: Re: [OSPF] Stephen Farrell's No Objection on draft-ietf-ospf-te-metric-extensions-09: (with COMMENT)
X-BeenThere: ospf@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: The Official IETF OSPG WG Mailing List <ospf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ospf>, <mailto:ospf-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ospf/>
List-Post: <mailto:ospf@ietf.org>
List-Help: <mailto:ospf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ospf>, <mailto:ospf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 04 Jan 2015 13:56:11 -0000
Hiya, Thanks - fine answer to my not-quite-discuss. Cheers, S. On 04/01/15 09:39, Adrian Farrel wrote: > Hi Stephen, > > I'd like the authors and shepherd to pitch in, but... > >> - I'd have thought that these TLVs would be sent more often than >> others, and that (if enormous amounts of money are in play) then >> use of OSPF authentication might be more likely needed (or some >> equivalent security mechanisms). I'd even speculate that if >> enormous amounts of money are in play, then confidentiality may >> become a requirement (since if I can observe say A bit settings >> then that might give me insight into traffic levels - sort of a >> lights burning at night in central bank implies interest-rate >> change attack). Can you say why none of that needs to be mentioned >> at all? Was any of that considered by the WG? (Can you send a >> relevant link to the archive?) > > I think you are raising two points: 1. Are the TLVs sent more often > than others and what are the implications? 2. What can be learned > from sniffing these TLVs? > > To the first point, I don't think they are sent more often than other > TE TLVs. Indeed metrics for loss and delay may be more stable than > others, and Section 5 addresses measurement intervals and projects > that on to announcement thresholds. > > So the risk is that changes in bandwidth availability will cause > rapid or frequent announcement of those metrics. However, just like > the original bandwidth metrics, implementations apply thresholds so > that small changes don't trigger re-announcement in order to avoid > stressing the network. Section 6 discusses this. > > Thus, I think we can discard 1. > > The second point is important: you can find out a lot about a network > by sniffing the IGP, and if your plan is to understand the state of > your competitor's network or to find the week spots to attack, then > this is a powerful tool. But in this matter I would argue that these > no TLVs are no more sensitive than other, pre-existing TLVs, although > (of course) the more TLVs, the more information is available to be > sniffed. > > So, the question is how do we protect IGP information as it is > advertised within a network. There are four elements: - IGP > information is retained within an administrative domain. - If a > router is compromised it has access to all of the information and > there is nothing we can do. - If a node attempts to join a network to > access the information it will be unknown and will not be able to > peer. - If a link is sniffed (which is a somewhat more sophisticated > attack) protection relies on encryption of the messages most probably > at layer 2, but potentially at IP (which is an option for OSPF) or > within the OSPF messages themselves. > > I think all of this is just "IGP security as normal", was discussed > by KARP, and is everyday business for network operators. > > [snip] > >> - The security considerations of RFC 3630, from 2003, is 11 lines >> long. Has nothing affected OSPF security in the last decade+ that >> would be worth noting here? > > That is a good point. There is plenty of newer security work. > > Adrian >
- [OSPF] Stephen Farrell's No Objection on draft-ie… Stephen Farrell
- Re: [OSPF] Stephen Farrell's No Objection on draf… Adrian Farrel
- Re: [OSPF] Stephen Farrell's No Objection on draf… Stephen Farrell
- Re: [OSPF] Stephen Farrell's No Objection on draf… John E Drake
- Re: [OSPF] Stephen Farrell's No Objection on draf… Acee Lindem (acee)
- Re: [OSPF] Stephen Farrell's No Objection on draf… Stephen Farrell
- Re: [OSPF] Stephen Farrell's No Objection on draf… John E Drake