It can also be used at other times to redefine an interface's address or other operating parameters. Only a user with appropriate privileges can modify the configuration of a network interface.
All users can run the second form of the command.
An interface can receive transmissions in differing protocols, each of which may require separate naming schemes. Enables interface after an ifconfig down . Occurs automatically when setting the address on an interface. If possible, the interface will be reset to disable reception as well. This action does not automatically disable routes using the interface.