No graphical way to allow TCP logins to Xserver in gdmsetup. No alternate method documented.

The option seems a poweruser one and not one for this tools

Seb, you are correct as most users do not use this. However, how would a poweruser go about making this change in karmic (conf file)? Is this documented anywhere?

I recommend having a default config file with commented instructions that a user can easily modify should they need this option enabled.

Not sure if it's documented but if it's not it should, letting the bug open for that, we are not going to add the option to the gtk interface though which is made for standard users

Found the gdm daemon to be documented in /usr/share/gnome/help-langpack/gdm/en_GB/gdm.xml although I am:
1) Unsure how a user should find this information (simplest way to access this in readable format)
2) Unsure if this works (needs testing)
3) Surprised not to see this documented elsewhere (wiki)

Below is the section this bug is concerned with. Attached is a simplified text file of the configuration options found in the xml file cited above.

Config file:
/etc/gdm/custom.conf

Security Options
[security]

Option:
DisallowTCP

Usage example:
DisallowTCP=true

Details:
If true, then always append -nolisten tcp to the command line when starting attached Xservers, thus disallowing TCP connection. This is a more secure configuration if you are not using remote connections.

Strike issue 1 - found it in a readable format:
http://library.gnome.org/admin/gdm/2.28/configuration.html.en#daemonconfig

Now only needs testing and wiki documentation.

Fix works in 10.04.

I created a file named /etc/gdm/custom.conf with the following contents on a server named lynx1:

[security]
DisallowTCP=false

I then rebooted lynx1.

From another system I gave the following commands

$ export DISPLAY=lynx1:0.0
$ xeyes

The eyes appeared on lynx1.

When I removed the custom.conf file and rebooted, I got the following message when I ran xeyes:

$ xeyes
Error: Can't open display: lynx1:0.0

I agree that this is an advanced configuration option and should not be in the standard ones, but available in some installable program from the ubuntu software center.