From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emiliano Romero Subject: Re: Nat+Iptables+Tcp Keepalive Problem Date: Thu, 04 Jun 2009 12:53:55 -0300 Message-ID: <4A27EE13.5000303@gmail.com> References: <4A27C999.3000609@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE To: netfilter-devel@vger.kernel.org Return-path: Received: from qw-out-2122.google.com ([74.125.92.24]:52792 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757605AbZFDQB0 (ORCPT ); Thu, 4 Jun 2009 12:01:26 -0400 Received: by qw-out-2122.google.com with SMTP id 5so595870qwd.37 for ; Thu, 04 Jun 2009 09:01:28 -0700 (PDT) In-Reply-To: Sender: netfilter-devel-owner@vger.kernel.org List-ID: Jozsef Kadlecsik escribi=F3: > The TCP keepalived packet in the output above is invalid: it's sequen= ce=20 > number is wrong. >=20 > Best regards, > Jozsef Thanks for your reply Jozsef. After your reply I look at RFC 1122, It s= ay: "Some TCP implementations, however, have included a keep-alive=20 mechanism. To confirm that an idle connection is still active, these=20 implementations send a probe segment designed to elicit a response from= =20 the peer TCP. Such a segment generally contains SEG.SEQ =3D SND.NXT-1" =2E.."so that this SEG.SEQ will be outside the window. Therefore, the=20 probe causes the receiver to return an acknowledgment segment" When I try with a linux box sending TCP KA, I see that this sets the AC= K=20 flag on TCP KeepAlive and that works correctly. I think that my remote=20 equipments (GPRS Modems) are making TCP KA is the wrong way. Or maybe=20 the GPRS Service Provider are touching my packets. Thanks Again. Regards -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html