From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sainfoin-smtp-out.extra.cea.fr (sainfoin-smtp-out.extra.cea.fr [132.167.192.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 89B833B29D for ; Mon, 12 Feb 2024 09:13:54 -0500 (EST) Received: from pisaure.intra.cea.fr (pisaure.intra.cea.fr [132.166.88.21]) by sainfoin-sys.extra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 41CEDrtq005773 for ; Mon, 12 Feb 2024 15:13:53 +0100 Received: from pisaure.intra.cea.fr (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id 24CBF209FBA for ; Mon, 12 Feb 2024 15:13:53 +0100 (CET) Received: from muguet2-smtp-out.intra.cea.fr (muguet2-smtp-out.intra.cea.fr [132.166.192.13]) by pisaure.intra.cea.fr (Postfix) with ESMTP id 1E16D209FB1 for ; Mon, 12 Feb 2024 15:13:53 +0100 (CET) Received: from [10.8.32.70] (is156570.intra.cea.fr [10.8.32.70]) by muguet2-sys.intra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 41CEDq2a029465 for ; Mon, 12 Feb 2024 15:13:53 +0100 Message-ID: <5323051a-5835-4e42-9850-2f3349a8bd77@gmail.com> Date: Mon, 12 Feb 2024 15:13:52 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: fr To: starlink@lists.bufferbloat.net References: From: Alexandre Petrescu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CEA-Virus: SOPHOS_SAVI_ERROR_OLD_VIRUS_DATA Subject: Re: [Starlink] Measuring the Satellite Links of a LEO Network X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Feb 2024 14:13:54 -0000 this is an issue for 6MAN WG at IETF, but this is the text with the issue in the paper: > From the user device or customer router at 192.168.1.1, > we can reach its GS gateway at 100.64.0.1 (or equivalently > fe80::200:5eff:fe00:101 for IPv6) That IPv6 link-local address has an 'ff:fe' in it; the prefix is 'fe80' and the rest is an 'Interface ID', in RFC parlance. That IID should be more random in its appearance.  It is called an 'opaque' IID, and specified in RFC 7217 "Stable and Opaque IIDs with SLAAC" of year 2014. That IPv6 address corresponds to earlier forms of these IIDs (RFC2464 of year 1998); they had that IID to be derived from a 48bit MAC address and inserted an 'ff:fe' string in it to become 64bit. Most embedded linux platforms (v2.x kernels?) still use that ff:fe.  Migrating these kernels is sometimes very difficult.  One might not want to migrate an kernel to a bloated and slower v3 or higher just for that little 'ff:fe'.  Maybe one wants to migrate just its IPv6 stack, but it's not easy. The reason of making this IID more opaque is to resist scanning attacks.  A scanning attack is when a user might have somehow an illegitimate starlink terminal and tries to connect to the legitimate starlink network.  Part of that trying is to know the IP address of the next hop.  With IPv6 it comes down to testing all these addresses.  If they have a constant 'ff:fe' in them, it is easier to find them by brute force than if they were opaque.  It is also true that if in IPv4 that next hop is always the same then the easiest attack is to simply use IPv4 instead of IPv6.  But this 'opaqueness' of the IID in the IPv6 ll address might still be needed when IPv4 is get rid of. This could be discussed at IETF, could be suggested to starlink to upgrade, etc. Alex Le 12/02/2024 à 07:59, J Pan via Starlink a écrit : > http://pan.uvic.ca/webb/viewtopic.php?p=124670#p124670 to appear at > ieee icc 2024. feedback welcome, especially during the camera-ready > stage this week. thanks! -j > -- > J Pan, UVic CSc, ECS566, 250-472-5796 (NO VM), Pan@UVic.CA, Web.UVic.CA/~pan > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink