From owner-freebsd-net@FreeBSD.ORG Mon Oct 22 18:18:38 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6C218419 for ; Mon, 22 Oct 2012 18:18:38 +0000 (UTC) (envelope-from s.khanchi@gmail.com) Received: from mail-ie0-f182.google.com (mail-ie0-f182.google.com [209.85.223.182]) by mx1.freebsd.org (Postfix) with ESMTP id 290608FC08 for ; Mon, 22 Oct 2012 18:18:37 +0000 (UTC) Received: by mail-ie0-f182.google.com with SMTP id k10so5471377iea.13 for ; Mon, 22 Oct 2012 11:18:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type; bh=pM1bQ+1oirf9udNvcy5AInbFe1HgQ5g9+0uqjjhhnFE=; b=LVIlBoxjsc6k0ZwHNvANCGavr+iypspWFdmU7g/G0UVmbVaUVRdhKY/UL5Ig19Km/K iQmbkGMKV3i6ESpz03rCRmMUWPNfP3cTLKBMYtDYFzWCJMBBWjeJj2a0AKT5VckPlPJ3 xwonrw10KoX11Q2z+rwwEiunYo9bMOSvSbv4CzieWcKnubVExShRHTdvytjTJXYKFgBb ivmG6BrRNiTxuvn+7qmaNgM/8RjEqlsnsFCBB0N74gIWJXDN3Tk0CHUZdba+uxz8BQTq Wg5KxE7aij5l8oTR3O13SiwZbpNf1n1rOnlxxW+5n6lN3QMaKXKiBmv9CMLBVWSGrRVR jcPA== Received: by 10.50.94.198 with SMTP id de6mr10047755igb.49.1350929917270; Mon, 22 Oct 2012 11:18:37 -0700 (PDT) MIME-Version: 1.0 Sender: s.khanchi@gmail.com Received: by 10.64.51.234 with HTTP; Mon, 22 Oct 2012 11:18:17 -0700 (PDT) In-Reply-To: <5080039E.9070202@networx.ch> References: <5080039E.9070202@networx.ch> From: h bagade Date: Mon, 22 Oct 2012 21:48:17 +0330 X-Google-Sender-Auth: GAOZxRl-RXXxUnlmHlNlTe0GEog Message-ID: Subject: Re: TCP_DROP_SYNFIN kernel option side effects?! To: Andre Oppermann Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: freebsd-net@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Oct 2012 18:18:38 -0000 Thanks Andre for your answer:) On Thu, Oct 18, 2012 at 4:56 PM, Andre Oppermann wrote: > On 16.10.2012 17:27, h bagade wrote: > >> Hi all, >> >> I need to add this option to kernel in order to defeating Nmap >> OS-Fingerprinting. My system is running as Web Server and also it is the >> gateway on the network. >> I want to know if setting this option has any side effects on other parts >> of the system? Is there any situation that SYN and FIN bits are set both >> in >> TCP packets? Is it a normal situation? >> > > SYN and FIN is not normal. Doing TCP_DROP_SYNFIN is not RFC compliant > but doesn't cause any problems. > > -- > Andre > >