CANNOT Get Remote X to Work -- Guru Needed

[J. K. Cliburn]

On 4/18/06, Bill Polhemus <bill at polhemus.cc> wrote:
> Most of the how-tos and other such information available on the 'net are
> old and outdated.
>
> I last had this working ca. FC3. I am using the WinAxE X-Window client
> (http://www.labf.com) on Windows XP, and trying to pull up my FC5 server's
> desktop from there. I just can't get the connection.
>
> I have the client software on the Windows XP box configured as shown on
> LabF's tutorials page, but when it comes to editing the various (and
> sundry!) config files on my FC5 server, I'm not sure I have even found
> them all.
>
> Is anyone doing this now? What advice can you give me?

I messed around and got this working between 2 FC5 boxes tonight. 
I've been meaning to do it since FC5 came out, and your query gave me
the motivation.

This procedure assumes you're on a private LAN, 192.168.1.0/24.  If
you're not, adjust IP addresses accordingly.  This procedure also
assumes you have physical access to the remote machine's console.

ON THE REMOTE MACHINE:  Login, open a terminal, and become root.  Run
"gdmsetup".  Select the "Remote" tab and choose "Same as Local". 
Click "Configure XDMCP" in lower right corner.  Make sure that "Honor
indirect requests" is unchecked.  Make sure "Listen on UDP port:" is
set to 177.  Click Close.  Click Close.  Edit /etc/sysconfig/iptables
and add this line before the line that contains "reject-with
icmp-host-prohibited".

-A RH-Firewall-1-INPUT -s 192.168.1.0/24 -p udp --dport 177 -j ACCEPT

(Again, pay attention to the IP address.)  Save the file.  Restart
iptables by executing "service iptables restart".

Restart X as follows.  Execute "init 3" from the command line.  A text
session appears.  Press enter if it appears hung.  Login as root. 
Execute "init 5" from the command line.  X starts.  Press CTRL-ALT-F1
so you can return to the text session and logout of the root session. 
Press CTRL-ALT-F7 to return to X.  Login, open a terminal, and become
root.

Execute the following command and verify that gdm-binary has opened
port 177/udp.

[root at petrel ~]# netstat --inet -pnl | grep 177
udp  0  0 0.0.0.0:177  0.0.0.0:*  3474/gdm-binary

If so, XDMCP is now configured on the remote host.  Log out of the remote host.

ON THE LOCAL MACHINE:  Login, open a terminal, and become root.  Edit
/etc/sysconfig/iptables and add the following line before the line
that contains "reject-with icmp-host-prohibited".

-A RH-Firewall-1-INPUT -s 192.168.1.0/24 -p tcp -m tcp --dport 6001 -j ACCEPT

Save the file.  Restart iptables.  Open a non-root shell.  From the
command line, kick off an X session connecting to the remote host's X
server, sending the display to local display :1.  Here's the command
to do it.

Xorg :1 -ac -query REMOTE_HOST_IP_ADDR

A new X session will start. You can toggle between the sessions by
pressing CTRL-ALT-F7 (for display 0, your original local session) and
CTRL-ALT-F8 (for display 1, your new XDMCP-served remote session).

Obviously, the steps on the local machine will be different since
you're on your Windows machine.  Adjust as necessary.

Hope this helps,
Jay