From owner-freebsd-stable Wed Jan 12 8:26: 3 2000 Delivered-To: freebsd-stable@freebsd.org Received: from point.osg.gov.bc.ca (point.osg.gov.bc.ca [142.32.102.44]) by hub.freebsd.org (Postfix) with ESMTP id E15FA14D3D; Wed, 12 Jan 2000 08:25:57 -0800 (PST) (envelope-from Cy.Schubert@uumail.gov.bc.ca) Received: (from daemon@localhost) by point.osg.gov.bc.ca (8.8.7/8.8.8) id IAA01240; Wed, 12 Jan 2000 08:25:07 -0800 Received: from passer.osg.gov.bc.ca(142.32.110.29) via SMTP by point.osg.gov.bc.ca, id smtpda01234; Wed Jan 12 08:24:51 2000 Received: (from uucp@localhost) by passer.osg.gov.bc.ca (8.9.3/8.9.1) id IAA43640; Wed, 12 Jan 2000 08:24:50 -0800 (PST) Received: from cwsys9.cwsent.com(10.2.2.1), claiming to be "cwsys.cwsent.com" via SMTP by passer9.cwsent.com, id smtpdS43637; Wed Jan 12 08:23:53 2000 Received: (from uucp@localhost) by cwsys.cwsent.com (8.9.3/8.9.1) id IAA04213; Wed, 12 Jan 2000 08:23:51 -0800 (PST) Message-Id: <200001121623.IAA04213@cwsys.cwsent.com> Received: from localhost.cwsent.com(127.0.0.1), claiming to be "cwsys" via SMTP by localhost.cwsent.com, id smtpdwT4209; Wed Jan 12 08:23:46 2000 X-Mailer: exmh version 2.1.1 10/15/1999 Reply-To: Cy Schubert - ITSD Open Systems Group From: Cy Schubert - ITSD Open Systems Group X-OS: FreeBSD 3.4-RELEASE X-Sender: cy To: Dag-Erling Smorgrav Cc: Cy Schubert - ITSD Open Systems Group , Brad Knowles , Holtor , freebsd-questions@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG Subject: Re: Kernel Option: TCP_DROP_SYNFIN In-reply-to: Your message of "12 Jan 2000 09:30:44 +0100." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 12 Jan 2000 08:23:45 -0800 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message , Dag-Erling Smorgrav writes: > Cy Schubert - ITSD Open Systems Group writes: > > In message , Dag-Erling Smorgrav > > writes: > > > It doesn't have anything to do with syn floods at all. It merely > > > prevents OS fingerprinting (at least the way nmap does it). > > The following ipfw rule will also prevent OS fingerprinting. > > > > deny log tcp from any to any in tcpflg fin,syn > > It does precisely the same thing as TCP_DROP_SYNFIN, except much slower. And it would log the event. Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 Sun/DEC Team, UNIX Group Internet: Cy.Schubert@uumail.gov.bc.ca ITSD Province of BC "e**(i*pi)+1=0" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message