From owner-freebsd-questions@freebsd.org Fri Jan 13 15:57:24 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id F0602CAD704 for ; Fri, 13 Jan 2017 15:57:24 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mailrelay15.qsc.de (mailrelay15.qsc.de [212.99.187.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.antispameurope.com", Issuer "TeleSec ServerPass DE-2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 640D417CF for ; Fri, 13 Jan 2017 15:57:23 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mx01.qsc.de ([213.148.129.14]) by mailrelay15.qsc.de; Fri, 13 Jan 2017 16:58:21 +0100 Received: from r56.edvax.de (port-92-195-83-137.dynamic.qsc.de [92.195.83.137]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx01.qsc.de (Postfix) with ESMTPS id D56FE3CC3F; Fri, 13 Jan 2017 16:57:12 +0100 (CET) Received: from r56.edvax.de (localhost [127.0.0.1]) by r56.edvax.de (8.14.5/8.14.5) with SMTP id v0DFvCpY002086; Fri, 13 Jan 2017 16:57:12 +0100 (CET) (envelope-from freebsd@edvax.de) Date: Fri, 13 Jan 2017 16:57:12 +0100 From: Polytropon To: galtsev@kicp.uchicago.edu Cc: "Damien Fleuriot" , Christoph Kukulies , "freebsd-questions@freebsd.org" Subject: Re: tunneling ports Message-Id: <20170113165712.eb279260.freebsd@edvax.de> In-Reply-To: <26405.128.135.52.6.1484322336.squirrel@cosmo.uchicago.edu> References: <26405.128.135.52.6.1484322336.squirrel@cosmo.uchicago.edu> Reply-To: Polytropon Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-cloud-security-sender: freebsd@edvax.de X-cloud-security-recipient: freebsd-questions@freebsd.org X-cloud-security-Virusscan: CLEAN X-cloud-security-disclaimer: This E-Mail was scanned by E-Mailservice on mailrelay15.qsc.de with CC99169DB52 X-cloud-security-connect: mx01.qsc.de[213.148.129.14], TLS=1, IP=213.148.129.14 X-cloud-security: scantime:.2198 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Jan 2017 15:57:25 -0000 On Fri, 13 Jan 2017 09:45:36 -0600 (CST), Valeri Galtsev wrote: > > On Fri, January 13, 2017 4:46 am, Damien Fleuriot wrote: > > On 13 January 2017 at 11:13, Christoph Kukulies wrote: > >> I don't know if this could be easily achieved, but imagine the situation > >> that you are in a network and the only ports being allowed for outgoing > >> traffic into the Internet are ports 80 and 443. > > > > Well well... somebody's trying to circumvent their netadmin's > > firewalls are they not ? > > > > It is not my place to question your motives, all I can offer is > > technical advice along with a warning. > > > > If your netadmin has somewhat advanced measures in place such as a > > transparent SSL proxy, you will get caught. > > And if I caught you doing that, I'd nuke your account on the spot. > > Just FYI ;) > > I would second that. I had a user on my server who was piercing firewall > of external place (at his new job) using ssh to my server with port > forwarding. I couldn't kick him out (sigh), but I disabled his ability to > forward ports on my server (sysadmins usually will take the side of > another sysadmin than rogue user). And restricted his account in many > other respects. You go some place to work at, you accept their rules, all > comes as a bundle. A totally valid point of view. Lacking a "backstory" for the original question, it's possible as well that the user is in a "web-only" or "mobile first" network (which doesn't even have to be a _work_ environment) where everything has to be HTTP(S), because nothing else exists. This seems to be a common mindset in wireless networks which are only intended for people with smartphones, because a normal computer cannot connect to WLAN because it doesn't have a WLAN cable. Then some kind of lazy and uneducated "admin person" found a setting in the firewall called "The Internet" and activated it... ;-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...