Ifconfig or interface configuration is a system administration
utility in Unix-like operating systems to configure, control, and
query TCP/IP network
interface parameters.Ifconfig gives you the various details like
Ip address , Mast address e.t.c.This can also be used in disabling and enabling
a given configuration.
The following example output samples display the state of a
single active interface each on a Linux-based host
(interface eth0).
[xprk477@omhq13aa ~]$ /sbin/ifconfig eth0
eth0 Link
encap:Ethernet HWaddr 02:00:30:00:03:AA
inet
addr:167.132.86.98 Bcast:167.132.86.127 Mask:255.255.255.224
inet6 addr:
fe80::30ff:fe00:3aa/64 Scope:Link
UP BROADCAST
RUNNING MULTICAST MTU:1500 Metric:1
RX
packets:837810597 errors:0 dropped:0 overruns:0 frame:0
TX
packets:1087417750 errors:0 dropped:0 overruns:0 carrier:0
collisions:0
txqueuelen:1000
RX
bytes:611883055593 (569.8 GiB) TX
bytes:705522440469 (657.0 GiB)
·Link
encap: the type of the hardware physical medium supported by this
interface (Ethernet, in this case)
·HWaddr: the unique identifier of the NIC card. Every NIC card has a
unique identifier assigned by the manufacturer, called MAC address. The MAC
value never changes.
·Mask: the netmask
·inet
addr: the IP address attached to the interface
·RX
packets: the number of packets received by this
interface
·TX
packets: the number of packets sent
·errors: the number of errors in sending or receiving
up/down – enables or disables a
specific interface. You can use the down to shutdown an interface like,
ifconfig eth0 down
If we need to bring that up we can use,
ifconfig eth0 up
add – sets a specific IP
address for the interface. To set an IP address of 192.170.1.121 to the
interface eth0, we can use
# ifconfig eth0 add 192.178.1.121
netmask – sets the netmask
parameter of the interface. Here is an example where you can set the netmask of
the eth0 interface to 255.255.255.0
# ifconfig eth0 netmask
255.255.255.0
Few More Examples Include
Assign ip-address to an Interface
Assign 172.178.3.2 as the IP address for the interface eth0.
# ifconfig eth0 172.178.3.2
Change Subnet mask of the interface eth0.
# ifconfig eth0 netmask 255.255.255.0
Change Broadcast address of the interface eth0.
# ifconfig eth0 broadcast 172.178.2.254
Assign ip-address, netmask and broadcast at the same time to interface eht0.
# ifconfig eth0 172.178.3.2 netmask 255.255.255.0 broadcast
Happy Learning , More To Come
