From owner-freebsd-hackers Sat May 23 13:49:19 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA29697 for freebsd-hackers-outgoing; Sat, 23 May 1998 13:49:19 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from smtp04.primenet.com (daemon@smtp04.primenet.com [206.165.6.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA29672 for ; Sat, 23 May 1998 13:49:15 -0700 (PDT) (envelope-from tlambert@usr07.primenet.com) Received: (from daemon@localhost) by smtp04.primenet.com (8.8.8/8.8.8) id NAA22880; Sat, 23 May 1998 13:49:14 -0700 (MST) Received: from usr07.primenet.com(206.165.6.207) via SMTP by smtp04.primenet.com, id smtpd022867; Sat May 23 13:49:07 1998 Received: (from tlambert@localhost) by usr07.primenet.com (8.8.5/8.8.5) id NAA12898; Sat, 23 May 1998 13:49:06 -0700 (MST) From: Terry Lambert Message-Id: <199805232049.NAA12898@usr07.primenet.com> Subject: Re: tcp states and sysctl's To: njs3@doc.ic.ac.uk (Niall Smart) Date: Sat, 23 May 1998 20:49:06 +0000 (GMT) Cc: hackers@FreeBSD.ORG In-Reply-To: from "Niall Smart" at May 22, 98 09:27:42 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I don't think a shutdown(2) sysctl is necessary. > > a) the BSD stack is currently compliant in this regard, if > anything need's changing it's the client. > > b) no-one has produced any evidence to show that all > these sockets in TIME_WAIT_2 are actully having a > negative impact in performance on the system. Actually, > I would seriously hope not, because otherwise this > is a relatively easy DoS. (Though probably not as > effective as a SYN flood.) > > If you do decide to put in a sysctl bear in mind that rsh uses > shutdown(2) to close down one end of a socket so you don't want > the timeout to be too short. Actually, there is a bug in zero-window probing. This occurs when talking to an HP Laserwriter. Basically, the FreeBSD box closes the connection, and can't send a FIN because the printer announces a zero window. A mechanism for converting a shutdown 1 to a shutdown 2 would be useful here. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message