From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: Linux kernel handling of IPv6 temporary addresses Date: Wed, 14 Nov 2012 18:08:24 -0500 (EST) Message-ID: <20121114.180824.1930899985436392426.davem@davemloft.net> References: <20121114231411.4328fc47@lola.kot> <20121114.162956.610530798200803185.davem@davemloft.net> <20121115010324.2707950c@lola.kot> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: kargig@void.gr Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:36459 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932436Ab2KNXIZ (ORCPT ); Wed, 14 Nov 2012 18:08:25 -0500 In-Reply-To: <20121115010324.2707950c@lola.kot> Sender: netdev-owner@vger.kernel.org List-ID: From: George Kargiotakis Date: Thu, 15 Nov 2012 01:03:24 +0200 > I think it's an issue that a LAN root user can disable a > locally enabled kernel "feature" for good. The kernel could provide a > somewhat more informative message on such an occasion taking place, > since it knows that max_addresses limit has been reached and it's not a > DAD failure. > > My point is that I'd like the kernel to handle this situation a bit > differently than it currently does. Read my example again, it's the same thing for ipv4. The root LAN user can disable all IPV4 communications to arbitrary IP addresses on the local LAN by emitting bogus ARP requests and poisoning everyone's caches. What's the difference between that and this arbitrary ipv6 issue? There is none at all. If you have a root person on your local LAN you're subject to injection of bogus addressing and routing information. This issue is not specific to ipv4 or ipv6 and is fundamental in nature. So it is misleading to bring this up as an ipv6 specific problem, it's not.