From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: Re-routing packets via netfilter (ip_rt_bug) Date: Wed, 27 Apr 2005 14:05:06 +0200 Message-ID: <426F7FF2.4070506@trash.net> References: <426D8672.1030001@trash.net> <20050426003925.GA13650@gondor.apana.org.au> <426E3F67.8090006@trash.net> <20050426232857.GA18358@gondor.apana.org.au> <426EE350.1070902@trash.net> <20050427010730.GA18919@gondor.apana.org.au> <426F68C5.4010109@trash.net> <20050427103056.GB22099@gondor.apana.org.au> <20050427113542.GB22433@gondor.apana.org.au> <20050427115414.GA22562@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com, netfilter-devel@lists.netfilter.org, Yair@arx.com, linux-kernel@vger.kernel.org, Jozsef Kadlecsik Return-path: To: Herbert Xu In-Reply-To: <20050427115414.GA22562@gondor.apana.org.au> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netdev.vger.kernel.org Herbert Xu wrote: > Here is another reason why these packets should go through FORWARD. > They were generated in response to packets in INPUT/FORWARD/OUTPUT. > The original packet has not undergone SNAT in any of these cases. > > However, if we feed the response packet through LOCAL_OUT it will > be subject to DNAT. This creates a NAT asymmetry and we may end > up with the wrong destination address. > > By pushing it through FORWARD it will only undergo SNAT which is > correct since the original packet would have undergone DNAT. This is only a problem since the recent NAT changes, but I agree that we should fix it by moving these packets to FORWARD. Regards Patrick