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View Full Version : How to set your LAN IP address to be static

2007-12-11, 20:50
These instructions are written for a Linksys BEFSR41 router and Ubuntu 7.10 operating system.

Suppose you have a dedicated server on your home network. You will need to forward the ports that are necessary for it to work properly. For example if you have the aMule p2p server running on a dedicated computer, you would forward in the router menu ports TCP 4662, UDP 4665, and UDP 4672. UPnP is another option for forwarding ports, if the server application supports it, but I'm not that comfortable using it.

DHCP is useful because it makes a computer simply plug in to the router and have access to the internet. But when you want to forward certain ports to a devoted computer on the network, the problem with DHCP is that the IP address expires after 2 days and then the ports could then be forwarded to the wrong computer. The local IP address can change periodically if there is more than one computer plugged into the router, and depending on which computer is booted up first.

In Ubuntu go to System->Administration->Network. Click on Wired connection and then Properties. Uncheck Enable roaming mode. For Configuration select Static IP address. Type in the IP address on the LAN you would like to have, such as Then it will give you the suggested Subnet mask of Afterwards type in the gateway router address, which is
*See the screenshot below: Ubuntu-Network.png

You can verify that the values of the Subnet mask and Gateway address are correct in your router on the first Setup page of the Linksys router menu.
*See the screenshot below: Linksys-Setup.png

Finally go into your router menu and set your DCHP range to be a higher number than that of the static IP address you gave. That way no computers will be given the same IP address on the LAN and create a clash. For example if you have selected a static IP address of, then you can start your DHCP range at
*See the screenshot below: Linksys-DHCP.png

for related topics, see:
Ubuntu (http://www.3-3-3.org/forum/showthread.php?t=1047) 2007-03-10

2008-01-07, 09:58
In Ubuntu version 8.04 Alpha 2, one can not change the local IP address using the System->Administration->Network menu. A helper application needs to be installed. To do so, go to Add/Remove Applications, and then select All available applications. Do a search for xnetcardconfig and install an application called Configure network card (description: A simple network card configuration for X). Once installed the program, will be located in the menu Applications->System Tools.