Tech Juice

If you have several wired and/or wireless interfaces, the default Ubuntu network-manager program will manage them all. To make the network manager ignore an interface, you must edit the /etc/network/interfaces file.

The /etc/network/interfaces file contains network interface configuration information for the both Ubuntu and Debian Linux. This is where you configure how your system is connected to the network.

Look at your current interfaces:

$ ifconfig

To make network-manager ignore wlan0:

$ sudo nano /etc/network/interfaces

And add the line:

iface wlan0 inet manual

The manual keyword denotes that network-manager should ignore the interface. After a reboot, the network manager will show device not managed for wlan0.…

By default, networking is disabled in Backtrack 4. The reason for this is that stealth is an important factor in penetration testing, so a system that starts sending out noisy DHCP requests after booting can be a bad thing.

Enabling networking

The easiest way to enable networking is to use the init script:

/etc/init.d/networking start

This will attempt to start the network interfaces in the file /etc/network/interfaces. Generally you don’t need to worry about the file’s contents; all relevant network interfaces will be enabled automatically and a DHCP lookup will start. If you are not using a wireless network card this is probably all you need to do. The rest of this page describes tools for a more manual approach.

Usually, your physical network card will be called eth0, and your wireless network card will be called wlan0.

ifconfig

Ifconfig is used to configure network interfaces. Without arguments, ifconfig shows the currently active interfaces:

$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:01:40:A4:b1:92
          inet addr:120.89.168.243  Bcast:120.89.175.255  Mask:255.255.240.0
          inet6 addr: 2001:610:1948:8000:211:50ff:fd34:b192/64 Scope:Global
          inet6