Cooking with Linux - My Desktop Lies over the Ocean
The IP address displayed may be an issue if you are trying to connect to a remote system that is on the other side of a home router or firewall. In those instances, you may need to set up a port redirect to allow port 5900 to connect to the PC you need to access. Because the way to do this varies from ISP to ISP and router manufacturer to router manufacturer, there isn't a quick way to explain it here. Your router documentation should cover this.
The other option is an e-mail invitation, which is essentially the same thing, except the connection details are sent via e-mail rather than read over the phone. The only catch here is that you are sending the means to access your system via e-mail during that one-hour period. If you choose this option, you'll receive a warning about plain-text e-mail over the Internet and the wisdom of encrypting said e-mail. Click Continue to get past the warning, and a KMail message appears (with instructions on how to connect), ready for you to click Send. If no one answers the invitation, it disappears within an hour.
Before we move on, click Close to get past all those invitations, and we'll have a look at another means of providing access—uninvited connections (that's our mysterious Configure button). If sending an e-mail invitation presents interesting security concerns, a wide-open, permanent invitation should ring additional bells. Nevertheless, in an office environment, it also may be the sanest method of giving yourself access. Click the Configure button to bring up the Configure dialog from the KDE Control Centre (Figure 3). Yes, that is correct. This configuration dialog also is available by running the KDE Control Centre from the K menu (or by using the kcontrol command name) and looking under the Internet & Network menu for Desktop Sharing.
If you check the Allow uninvited connections box, you still have to assign a password for connecting. Furthermore, you have the opportunity to “Confirm uninvited connections before accepting”. You also can decide whether to give those uninvited connections the ability to control the desktop. If you don't check the latter, users can give you control at any time by selecting the desktop sharing icon that appears in their system tray.
On the GNOME side of things, there's a program called Remote Desktop Sharing. On a typical GNOME setup, click System on the top menu bar, then look under Preferences for Remote Desktop (if you like, you can run the command directly using /usr/lib/vino/vino-server). The Remote Desktop Preferences menu appears as shown in Figure 4. Needless to say, I love the name.
Some of this is going to look very familiar, because many of the questions mirror those of the KDE Control Centre configuration for desktop sharing. If you simply want to show what your desktop is doing (and let somebody follow along), click the Allow other users to view your desktop check box. If you are looking for help, or you want to help the person on the other end, make sure the person sharing checks the Allow box, second from the top. Users who want to leave a sharing session open all the time may decide to check the Ask you for confirmation button, so that a remote user has to have their permission. Finally, if this is an unattended connection, you'll surely want to assign a password to allow this connection to happen. Although it may not seem apparent here, you also can generate an e-mail invitation by clicking the command listed under Users can view your desktop using this command.
To connect to a remote shared desktop, you can use any VNC client—the GNOME vino-server program suggests vncviewer as the command to use—including a Java-enabled browser. The invitation e-mail tells you how to do this. The slicker, desktop-oriented way to do this is by using the tools provided by your desktop environment. The KDE Remote Desktop Connection program (Krdc) can be started from the Internet K Menu, where you'll see it listed as Remote Desktop Connection. From the dialog that pops up, you can enter the host connection information as shown in Figure 5.
The connection program can be used simply by entering the sharing host's address and pressing Connect. Another window appears asking you to specify the quality of your connection—whether it be a fast LAN connection, a slow dial-up connection or something in between. When you do connect, what happens depends on how the invitation was created. If the confirm option was set, a warning message appears on the remote desktop asking for confirmation. On the client side, you then may be asked for a password.