Which of the following commands is used to set down the interface and flush all its addresses?

A.
ifup

B.
ifdown

C.
ifconfig

D.
down

Explanation:

The ifdown command is used to set down the interface and flush all its addresses. It is possible to
let
ifdown check the interface if the interface is still used before setting it down. If the interface is used

it may then discard the using processes or refuse setting it down.
To enable this feature, check /etc/sysconfig/network/config file.
Answer option A is incorrect. The ifup command is used to bring up a preconfigured interface for
networking. It is usually invoked by the network script at boot time or by the PCMCIA/hotplug
system. It can also be used to start interfaces manually on the command line. It activates the link,
adds addresses and other parameters and sets up the routes for an interface.
Answer option C is incorrect. The ifconfig commands displays the basic settings of a network
device.
Answer option D is incorrect. There is no such command as down.