This is an in-depth tutorial covering the simple act of setting up Remote Desktop in 7.10 and forward the ports on your router so you may access your ubuntu machine from anywhere. I find this handy when in a different city and needing to access a file on my local network. I merely plug my USB thumb drive into the computer, run my portable Ultra VNC Viewer, and connect. I also use it to work in Linux instead of windows (because it is setup to the same screen size as my laptop. I just full screen the VNC connection and work in ubuntu; however I do have to stand connection issues).
So I will go slowly and step by step through this procedure as well. 7.10 makes it EXTREMELY easy to get it up and running, so you should be able to get it up and running in 5 minutes or so.
1. Boot up ubuntu of course and login.
2. As shown in the picture, on the ubuntu menu, go to System > Preferences > Remote Desktop.

3. This will bring you to the Preferences window. Check “Allow other users to view your desktop”
4. Check “Allow other users to control your desktop” if you want the user to be able to actually control the mouse and keyboard once logged in. If you are merely letting people login to view your desktop then you can leave it unchecked.
5. Uncheck “Ask for confirmation”. If you have this checked it will make a confirmation window popup every time a user tries to connect remotely. The local user will need to allow them to connect before they can begin their remote session. If there is no local user to confirm this, and you are on a trip and forgot to uncheck it… you sir are SOL.
6. Check “Require the user to enter this password” and enter in the password in the text box below. The remote user will be prompted to enter this password before they are given access to the remote machine. This is a MUST. Otherwise, anyone who connects to that address will be able to control your machine remotely as they please.

7. Click the close button to close the Preferences window. Your remote connection is now setup for your LAN and you may access that ubuntu machine from any other pc on your network without port forwarding.
For those of you familiar with port forwarding, don’t bother reading the next section because it’s merely a step by step. Basically, forward a port of your choice to port 5900 for the ubuntu machine you are setting Remote Desktop on.
8. Now for some simple router changes. First, we are going to need to gather some information. The gateway and the IP address of the ubuntu machine. This is easy to find out. First, lets open up our network connection by going to System > Administration > Network.
9. Click on the connection type you are using. In my case I am using a wired connection. I would suggest using a wired connection if you are planning to routinely use this machine remotely because it tends to be a lot more reliable than wireless.
10. This will bring up a window with your connection settings. If you are using DCHP then you can’t gather much from this. I recommend switching over to Static IP address (but beware, that this must be enabled in your router, but is usually already enabled by default). I’m not going to go in depth with a lot of router settings, so if you have questions about functions such as router access or static configuration, Google it!

11. Write down the IP Address of your machine, and also the Gateway address. We will need this soon.
12. Open up a web browser and type in http:// and your gateway after. For example http://192.168.1.1 this should bring up the login screen.
13. You should be able to login now. Make sure you have permission to edit your router. If you have another LAN administrator, check with them before logging in and making any changes.
14. This is a part that is different for everyone depending on your router type and model. I am using DD-WRT on a crappy wireless router. All you need to do is go to the section regarding port forwarding.
15. Once you navigate to this section, we have a port to add (to allow the outside connections to this computer on your LAN). The default VNC port is 5900. Your router may have different names for some of this, but it all should be relatively similar. My example is listed in the picture below. So, let me explain what it all means.

Application: A brief description of what you are forwarding so that you can quickly reference it. I just named it ubuntu because I know that port 5900 is VNC so I don’t need to know the application.
Port from: this is the port the machine not on your LAN will try to make a connection from. It is suggested to make it something that is not the normal 5900 because this is a dead giveaway for attackers. I just made this one 8000. (Be careful, some ports are reserved for certain applications, so if you aren’t sure, Google the port before you choose for sure).
Protocol: TCP and UDP. Can’t remember if VNC needs both, so just go ahead and click both.
IP Address: this is where you will enter in the IP address you previously wrote down. This tells the router what machine to make a connection with.
Port to: set this to 5900. This is the port that the remote desktop application will connect on.
Enable: obviously we want to enable this.
16. After making the necessary changes, you will need to save the new settings, and most likely restart the router for it to take effect. It is a good idea to log back in and make sure the settings saved correctly.
17. Alright, so now you have setup Remote Desktop on your machine, and forwarded the port on your router so you may access from the outside. So, how do you connect? Well… this is a complex question. It really depends on your connection, and if you are on a residential where the external IP changes every few hours or days. If it does then you will need to find a solution such as NO-IP that sets a name while it tracks changes in your IP, and changes the name to that. I won’t go in depth with that so ill just post this link if you need more information. http://www.no-ip.com For a temporary test, lets just use www.whatismyip.com
18. Copy paste your external IP (given from the link above) and :port number into your vnc viewer and test. For example 12.35.33.58:8000 will be your connection if “12.35.33.58″ is your external IP. NOTE** you cannot connect to your external IP from a machine in your LAN. You must test from a computer outside of your network for it to work. After all, this is what you set up the port forwarding for.
19. At this point, if you have a successful test, you are setup and good to work remotely on your ubuntu machine. If you cannot connect, you may want to check that your IP has not changed, and go through our configuration process once again. If you have any simple questions you may refer to the ubuntuforums (which has great user support) or try googling some troubleshooting options.
Whew, that was a little more in-depth than I wanted to get with this simple procedure, but I do want to give as much detail and help for new users as possible. Hopefully this helps one or two of you. Please check back for further Ubuntu 7.10 user tutorials in the near future.
Here is the VNC Viewer I use and enjoy. RealVNC is decent as well. http://www.uvnc.com/