ifconfig COMMAND

ifconfig COMMAND:
ifconfig command displays information about the network interfaces attached to the system and also used to configure the network interface.

SYNTAX:
The Syntax is
ifconfig [options]

OPTIONS:

-a	dispalys information about both active and inactive Interface
[interface-name]	dispalys information about interface
[interface-name] up	Activates the interface
[interface-name] down	Inactivates the interface
[interface-name] [IP Address] up	Assigns IP address to the interface and activates it

EXAMPLE:

1. To get information of active network-interfaces:
   

   ifconfig

   The sample output of above command:
   

   eth0 Link encap:Ethernet HWaddr 00:14:85:9C:CC:55 inet addr:192.168.0.12 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::214:85ff:fe9c:cc55/64 Scope:Link UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:7856 errors:0 dropped:0 overruns:0 frame:0 TX packets:7856 errors:0 dropped:0 overruns:0 carrier:0 RX bytes:492016 (480.4 KiB) TX bytes:398 (398.0 b) Interrupt:201 Memory:e1000000-0 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0 inet6 addr: ::1/128 Scope:Host UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1455 errors:0 dropped:0 overruns:0 frame:0 TX packets:5 errors:0 dropped:0 overruns:0 carrier:0 RX bytes:1917382 (1.8 MiB) TX bytes:1917382 (1.8 MiB)

   In above output:
   Link encap:Ethernet	-Specifies the type Interface
   HWaddr 00:14:85:9C:CC:55	-Specifies the Hardware or MAC address
   inet addr:192.168.0.12	-Specifies the IP address assigend to network-interface

2. To Assign IP address to Network Interface[Ethernet Card]:
   

   ifconfig eth0 192.168.0.12 up

   The above command will Assign IP address 192.168.0.12 to Ethernet card with name eth0.
3. To inactivate the Network Interface[Ethernet Card]:
   

   ifconfig eth0 down

   The above command inactivates the ethernet card.