title: ssh_exchange_identification
body: <p>My windows 7 system with cygwin is behind a corporate firewall, I installed corkscrew and my config file reads</p>
  
  <pre><code>User git
      HostName ssh.github.com
      Port 443
      ProxyCommand /d/cygwin/bin/corkscrew http://x.x.x.x 80 %h %p /c/Users/ad cd/.ssh/id_rsa.
  </code></pre>
  
  <p>But when I do <code>git clone ssh://git@github.com:443/rails/rails.git</code>,
  I get the error</p>
  
  <pre><code>Cloning into rails...
  ssh_exchange_identification: Connection closed by remote host
  fatal: The remote end hung up unexpectedly
  </code></pre>