IFCONFIG is a command-line tool, which is used for network interface management. Following are some of the options used with the command:

• up: This option is used to activate the specified interface.
• down: This option is used to deactivate the specified interface.
• lo: This option is used to view the loopback interface.

The IFCONFIG command is also used to configure an interface.

Syntax:

IFCONFIG interface options

For example, to configure a Linux computer’s first network interface with an IP address 200.200.200.123 and subnet mask 255.255.255.0, the following command is used:

IFCONFIG eth0 200.200.200.123 netmask 255.255.255.0