From owner-freebsd-security Thu Jan 18 6:17: 9 2001 Delivered-To: freebsd-security@freebsd.org Received: from jamus.xpert.com (jamus.xpert.com [199.203.132.17]) by hub.freebsd.org (Postfix) with ESMTP id 6E5CF37B402 for ; Thu, 18 Jan 2001 06:16:49 -0800 (PST) Received: from roman (helo=localhost) by jamus.xpert.com with local-esmtp (Exim 3.12 #5) id 14JFrp-0004Qw-00; Thu, 18 Jan 2001 16:16:45 +0200 Date: Thu, 18 Jan 2001 16:16:45 +0200 (IST) From: Roman Shterenzon To: Pavol Adamec Cc: Subject: Re: TCP_DROP_SYNFIN In-Reply-To: <3A63FFF9.8E64A6AA@tempest.sk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 16 Jan 2001, Pavol Adamec wrote: > I'm not sure what you excatly ment by that but: > > TCP_DROP_SYNFIN forces kernel to drop packets with BOTH SYN and > FIN flags set. nmap -sS is a "half-open scan" - it send packets > with only SYN flag set. > What you likely want is TCP_RESTRICT_RST - not to emit RST for SYN > packets to non-listening ports. I thought that this is what blackhole(4) is for. Can you explain? > > Paul > > Dennis Jun wrote: > > > > I have compiled this option in my kernel on 3 differents FreeBSD boxes > > (4.1.1-STABLE, 4.1-RELEASEs) and I have noticed that it doesn't work all > > the time. Specifically with this scan nmap -v -O -sS . Is it just me or > > does this not work for other people as well? > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-security" in the body of the message > > Dennis Jun wrote: > > > > I have compiled this option in my kernel on 3 differents FreeBSD boxes > > (4.1.1-STABLE, 4.1-RELEASEs) and I have noticed that it doesn't work all > > the time. Specifically with this scan nmap -v -O -sS . Is it just me or > > does this not work for other people as well? > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-security" in the body of the message > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-security" in the body of the message > --Roman Shterenzon, UNIX System Administrator and Consultant [ Xpert UNIX Systems Ltd., Herzlia, Israel. Tel: +972-9-9522361 ] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message