Need help to connect internet in ubuntu with dsl modem?

Go to system preferences, network connections. There edit a wired connection. You will have to provide a device MAC address. This you can find out by the ifconfig command executed from a terminal. For ipv4 settings choose manual Choose Manual and click Add. Type in these details : Address = 192.168.1.1 , Netmask = 255.255.255.0, Gateway = 192.168.1.1. You will have to give DNS numbers. Contact your service provider for this. Or use open DNS (www.opendns.com). Save and close. You can add a network manager icon on your task bar for easy access.