Here is a howto about the configuring ip using networking related files in Ubuntu / Debian systems.
The interfaces file contains the details of all configurations...

File: /etc/network/interfaces
This file contains network interface configuration information for the ifup and ifdown commands. This is where you configure how your system is connected to the network.

It's always been possible to get Linux desktops to work on Windows-based networks. I do it all the time. But, it's not a job for an average Linux user or a Windows network administrator's whose MCSE (Microsoft Certified Systems Engineer) certification still has wet-ink.

Wireless in Linux has finally reached a point where it’s easy to setup and use. Most distributions provide graphical applications to manage your wireless connection. Ubuntu is one of them with its simple but effective and easy to use network-admin.

Nmap, or the Network Mapper, is a powerful command-line tool for diagnosing network problems, finding security vulnerabilities, and host of other uses. Its many options and scanning methods can be daunting to even the most experienced of end users, but nmapFE is a graphical interface for nmap that makes it easy to use even the most powerful aspects of the network mapper, and can be a life-saver when you run into networking problems.

In setting up their wireless connection for the first time, Im discovering many individuals having problems connecting through Network Manager or other GUI wireless connection tools. In fact my Network Manager is intermittently buggy, connecting sometimes and not others.

Have you ever needed to wirelessly network a Windows PC's directly to a Ubuntu machine?  In other words, you lack a router, switch, or other networking mechanism, each PC has a wireless device and you need to trade a file or play a network game?  Read on

So, you have read lartc's guide on 'Routing for multiple uplinks/providers' and it all makes sense (and does work). However, there's a catch for you: Instead of having static network configurations, your ISPs use DHCP to set your network connections and you don't intend to sit all day long waiting for DHCP event to happen to reconfigure the whole thing, do you? That's what I thought

Zenmap is the official graphical user interface (GUI) for the Nmap Security Scanner. It is a multi-platform, free and open-source application designed to make Nmap easy for beginners to use while providing advanced features for experienced Nmap users. The purpose of Zenmap is not to replace Nmap.

Umit is a user-friendly graphical interface to Nmap that lets you perform network port scanning. The utility's most useful features are its stored scan profiles and the ability to search and compare saved network scans.