From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leo Baltus Subject: Re: ip6tables breaks dnssec? Date: Wed, 27 Apr 2011 12:56:44 +0200 Message-ID: <20110427105644.GA9859@omroep.nl> References: <20110427085755.GD2418@omroep.nl> <4DB7F347.1080107@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Engelhardt , netfilter-devel@vger.kernel.org To: Ulrich Weber Return-path: Received: from out1a.mail.omroep.nl ([145.58.30.184]:59514 "EHLO out1a.mail.omroep.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753760Ab1D0K4m (ORCPT ); Wed, 27 Apr 2011 06:56:42 -0400 Content-Disposition: inline In-Reply-To: <4DB7F347.1080107@gmail.com> Sender: netfilter-devel-owner@vger.kernel.org List-ID: Op 27/04/2011 om 12:43:19 +0200, schreef Ulrich Weber: > Each fragmented IPv6 packets will traverse netfilter separately, > in contrast to IPv4, where its only one refragmented packet. > I seem to have missed that. > "ip6tables -A INPUT -j ACCEPT -p udp --dport 53" will only match the > first fragment, where the UDP header can be found. To match the > additional fragments, you have to insert these rules: > > ip6tables -I INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT > ip6tables -I OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT > Thanks. That was it. > On 04/27/2011 12:08 PM, Jan Engelhardt wrote: > > On Wednesday 2011-04-27 10:57, Leo Baltus wrote: > > > >> Hi, > >> > >> When doing recusive dns queries to dnssec-enbled servers it looks like > >> ip6tables does not assemble udp packets before filtering takes place. > >> This results in fragments being dropped. > > > > You need to have nf_defrag_ipv6 loaded for automatic defragmentation. > > There are only a few components that depend on it - nf_conntrack and > > TPROXY, so it may not be autoloaded if you do not use either. > > -- > > To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Leo Baltus, internetbeheerder /\ NPO ICT Internet Services /NPO/\ Sumatralaan 45, 1217 GP Hilversum, Filmcentrum, west \ /\/ beheer@omroep.nl, 035-6773555 \/