How to redirect GUI across firewall?

[Jenny C]

Hi, I am inside corporate firewall and need to access a machine outside. I only have a windows notebook. Using refletionX, I connected to an internal UNIX box and then used socks to initiate a telnet windows to the external machine. But if I use GUI utilities like SAM, how do I re-direct the display across the firewall so that I could at least see if from refletionX? Thank you in advance.

[Ceesjan van Hattum · Accepted solution]

XDMCP uses UDP port 177 and TCP port 6000 for communications. So if your Reflection X sessions are going through a router or a firewall, those ports must be open for internal users so that the remote host can respond to your desktop sessions

See for more info:
http://www.serverworldmagazine.com/monthly/2002/01/reflectionx.shtml

But beware, not a lot of security-guys are willing to open tcp-ports on high numbers like 6000..
You need to ask yourself the question: why high numbers are not commenly wanted....

Regards,
Ceesjan

[Bill Hassell]

Xwindows is a very poor protocol to allow through a firewall and your security folks may rightfully reject your request. Users of Xwindows are not aware that without specific steps, anyone can read your display and even place rogue windows on your display asking for root passwords. Since these look normal, you would not necessarily be suspicious.

Do you actually need a GUI program? It is far more efficient (and secure) to use telnet and if needed, ssh to secure the transmissions through the firewall.