Ubuntu Unleashed 2019 Edition: Covering 18.04, 18.10, 19.04

Feel    free    to  skip    ahead   to  the ip  section.

ifconfig

ifconfig is used to configure a network interface. You can use it to do the
following:

    Activate    or  deactivate  your    NIC or  change  your    NIC’s   mode

    Change  your    machine’s   IP  address,    netmask,    or  broadcast   address

    Create  an  IP  alias   to  allow   more    than    one IP  address on  your    NIC

    Set a   destination address for a   point-to-point  connection

You can change as many or as few of these options as you want with a single
command. The basic structure for the command is as follows:

Click here to view code image
ifconfig [network device] options

Table 18.1 shows a subset of ifconfig options and examples of their uses.

Table 18.1 ifconfig Options

Use Option Example

Create  alias [network  device] ifconfig    eth0:0_:[number]

10.10.10.10

Change  IP

address

ifconfig    eth0    10.10.10.12

Change  the

netmask

netmask [netmask] ifconfig  eth0    netmask

255.255.255.0

Change  the

broadcast

broadcast [address]ifconfig eth0    broadcast

10.10.10.255

Take

interface

down

down ifconfig   eth0    down

Bring

interface   up

up  (add    IP

address)

ifconfig    eth0    up  (ifconfig

eth0    10.10.10.10)