From owner-freebsd-current@FreeBSD.ORG Thu Nov 20 23:05:54 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5F67416A4CE; Thu, 20 Nov 2003 23:05:54 -0800 (PST) Received: from cirb503493.alcatel.com.au (c211-30-75-229.belrs2.nsw.optusnet.com.au [211.30.75.229]) by mx1.FreeBSD.org (Postfix) with ESMTP id D23FE43FD7; Thu, 20 Nov 2003 23:05:52 -0800 (PST) (envelope-from PeterJeremy@optushome.com.au) Received: from cirb503493.alcatel.com.au (localhost.alcatel.com.au [127.0.0.1])hAL75Sf1067513; Fri, 21 Nov 2003 18:05:34 +1100 (EST) (envelope-from jeremyp@cirb503493.alcatel.com.au) Received: (from jeremyp@localhost)hAL75MWx067512; Fri, 21 Nov 2003 18:05:22 +1100 (EST) (envelope-from jeremyp) Date: Fri, 21 Nov 2003 18:05:22 +1100 From: Peter Jeremy To: Len Sassaman Message-ID: <20031121070522.GF39616@cirb503493.alcatel.com.au> References: <0C8643E8-1B1A-11D8-B160-000A959E7C72@anonymizer.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0C8643E8-1B1A-11D8-B160-000A959E7C72@anonymizer.com> User-Agent: Mutt/1.4.1i cc: freebsd-hackers@freebsd.org cc: freebsd-current@freebsd.org Subject: Re: Help request: problems with a 5.1 server and large numbers of ssh users. X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Nov 2003 07:05:54 -0000 On Wed, Nov 19, 2003 at 09:26:10PM -0800, Len Sassaman wrote: >It is my intuition from this behavior that the sshd master process >listening for connections is unable to spawn a new process to complete >the authentication step, and thus the connection is being dropped. >There is no information of use in dmesg, nor in the system logs. (I've >cranked up LogLevel to DEBUG3 in sshd_config). I don't have a solution but a couple of suggestions for further investigation: With 150 users logged in (so that no more can log in), what happens if you start another sshd on a different port (or kill the master sshd and start another one on port 22). What happens if you "ktrace -i" sshd and compare the results when the 150th client logs in to the results when the 151st client fails to log in. Some doctoring of PIDs with sed or similar will allow you to diff the output without getting buried in non-differences. I presume that the clients are attempting to connect from more than one host (ie it's not a resource problem in the client). Peter