Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com To: cygwin@cygwin.com From: Andrew Schulman Subject: Re: Cygwin and firewalls Date: Sat, 18 Jun 2005 14:51:19 -0400 Lines: 18 Message-ID: References: <42B41CCC.9D7D70A7@dessent.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit User-Agent: KNode/0.9.1 X-Archive: encrypt X-IsSubscribed: yes >> Why is this a Cygwin question? A firewall is a firewall. Network >> applications, both Cygwin and non-Cygwin, have to deal with it. I don't >> know what a Cygwin-hostile firewall would look like. > > Cygwin uses sockets to implement many of its functions, such as IPC. > Some overzealous firewalls install themselves deeply into the winsock > stack (I believe it's called 'layered service provider' API) and install > hooks throughout. This can cause things to break if the firewall > implementation is not done properly and without bugs, or causes the > semantics of socket operations to change. See for example, the threads > about crappy VPN clients causing cygwin programs to hang, or the > Zonealarm firewall causing the X11 server to hang at startup. Sadly the > archives are littered with examples of poorly written firewall-type > software that causes things to break, so it's not such a stupid > question. OK, thanks. Learn something new every day. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/