Networking X Manually

Whenever possible, you should use the ssh technique already discussed for remote application display because the ssh command performs this task both easily and securely.

If you aren't able to use ssh for some reason and thus can't automate the security policy needs associated with the X Window System's remote display facility, you can use an alternate methodmanipulation of the DISPLAY environment variable and xhost security toolto allow and start remotely displayed applications manually. This can often be the case when you're interacting with older Unix systems in which ssh is not supported or economical.

If you want to run a Linux application on one system and display it on another this way, you must do two things:

• Configure the security features on the display system to allow remote applications to open application windows on the screen. You do this using the xhost command. By default, Red Hat Fedora 4 does not allow programs on remote systems to open application windows.

• Set the DISPLAY environment variable, which is used by applications to locate and use the graphical display, to point to the graphical display you want applications to use.

Preparing to Network X Manually

To network X connections manually between Red Hat Fedora 4 systems, you must make one important adjustment to your firewall security configuration. In Red Hat Fedora 4, X does not accept manual remote connections by default. To use X remotely without ssh, you must first change this setting. You can enable incoming X connections by following these steps:

1.	Start the tool by choosing Desktop, System Settings, Security Level.
2.	In the Other Ports box, enter 6000:tcp to allow incoming TCP connections on port 6000, which is used by the X Window System.

You are now ready to begin networking X Window System applications manually.

These Steps Are Designed for Red Hat Fedora 4

The steps given to unlock the manual networking capabilities of the X Window System are intended for Red Hat Fedora 4 users. These steps likely will differ in other Linux operating systems or on other Unix platforms. This is one of the reasons many users prefer to simply use ssh to network their X applications: It's much easier!