From owner-freebsd-questions@FreeBSD.ORG Sun Mar 11 19:48:00 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 63ADC16A405; Sun, 11 Mar 2007 19:48:00 +0000 (UTC) (envelope-from bill@ayn.mi.celestial.com) Received: from ayn.mi.celestial.com (hayek.celestial.com [192.136.111.12]) by mx1.freebsd.org (Postfix) with ESMTP id 4769C13C457; Sun, 11 Mar 2007 19:48:00 +0000 (UTC) (envelope-from bill@ayn.mi.celestial.com) Received: from localhost (localhost [127.0.0.1]) by ayn.mi.celestial.com (Postfix) with ESMTP id E1E6568600E47; Sun, 11 Mar 2007 12:48:49 -0700 (PDT) X-Virus-Scanned: amavisd-new at mi.celestial.com Received: from ayn.mi.celestial.com ([127.0.0.1]) by localhost (ayn.mi.celestial.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id kW1p2EThNzRh; Sun, 11 Mar 2007 12:48:49 -0700 (PDT) Received: by ayn.mi.celestial.com (Postfix, from userid 203) id C534C68600419; Sun, 11 Mar 2007 12:48:49 -0700 (PDT) Date: Sun, 11 Mar 2007 12:48:49 -0700 From: Bill Campbell To: freebsd-questions@freebsd.org, questions@FreeBSD.org Message-ID: <20070311194849.GB881@ayn.mi.celestial.com> Mail-Followup-To: freebsd-questions@freebsd.org, questions@FreeBSD.org References: <035c01c763fd$b7341cf0$259c56d0$@net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <035c01c763fd$b7341cf0$259c56d0$@net> User-Agent: Mutt/1.5.11 OpenPKG/2.5 Cc: Subject: Re: OpenSSH Problem with disconnects X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd@celestial.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 Mar 2007 19:48:00 -0000 On Sun, Mar 11, 2007, Alexander Schlichting wrote: > > >Hi, > > > >I am having a big problem with the OpenSSH Daemon on my server. Whenever I >am connected to the server and the connection is idle for a few seconds it >gets disconnected. It's almost impossible to work from remote on the server. It's been my experience that this has been related to NAT (Network Address Translation), IP masquerading or possibly other firewall settings, and may well not be FreeBSD specific. One of my customers had a problem like this in the last week or so and tracked it down to settings on their LinkSys BEFVP41 VPN router which had some firewall setting that caused ssh connections to drop (it wasn't NAT on this as I've not had this problem with other BEFVP41s). We ran all internal traffic through a Caldera OpenLinux 2.3 system, with a 2.4 Linux kernel with ipchains IP masquerading, and it would drop ssh connections after several minuted of inactivity (I would often run top on the remote system just to keep the connection alive when I wasn't doing something that would create activity). When we switched our border machine to a SLES9 machine with a 2.6 Linux kernel and iptables NAT the problem went away. There are also ssh_config and sshd_config parameters that relate to tcp timeouts and keep alive actions. Bill -- INTERNET: bill@Celestial.COM Bill Campbell; Celestial Software, LLC URL: http://www.celestial.com/ PO Box 820; 6641 E. Mercer Way FAX: (206) 232-9186 Mercer Island, WA 98040-0820; (206) 236-1676 ``I presume you all know who I am. I am humble Abraham Lincoln. I have been solicited by many friends to become a candidate for the legistlature. My politics are short and sweet, like the old woman's dance. I am in favor of a national bank ... in favor of the internal improvements system, and a high protective tariff.'' -- Abraham Lincoln, 1832