From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: [PATCH 05/19] netfilter: nf_conntrack_ipv6: improve fragmentation handling Date: Wed, 22 Aug 2012 00:21:37 +0200 Message-ID: <1345587697.3069.297.camel@localhost> References: <1344542943-11588-1-git-send-email-kaber@trash.net> <1344542943-11588-6-git-send-email-kaber@trash.net> <1345190795.3069.228.camel@localhost> <1345405069.3069.241.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, Julian Anastasov , Hans Schillstrom , Hans Schillstrom To: Patrick McHardy Return-path: In-Reply-To: Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sun, 2012-08-19 at 21:44 +0200, Patrick McHardy wrote: > On Sun, 19 Aug 2012, Jesper Dangaard Brouer wrote: > > On Sat, 2012-08-18 at 14:26 +0200, Patrick McHardy wrote: [...] > > Don't I need to load some of the helper modules, or just the > > nf_conntrack_ipv6 module, or perhaps only nf_defrag_ipv6 ? > > Not with the entire patchset, just IPv6 conntrack is enough. Aith IPv6 NAT > the first packet of a connection must always be defragemented, independant > of an assigned helper. When loading "nf_conntrack_ipv6" I run into issues. When sending a fragmented UDP packet. With these patches, the IPVS stack will no longer see the fragmented packets, but instead see one large SKB. This will trigger a MTU path check in e.g. ip_vs_dr_xmit_v6() and an ICMPv6 too big packet is send back. IPVS: ip_vs_dr_xmit_v6(): frag needed Perhaps we could change/fix the MTU check in IPVS? (This would also solve issues I've seen with TSO/GSO frames, hitting this code path). -- Best regards, Jesper Dangaard Brouer MSc.CS, Sr. Network Kernel Developer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer