Networking - Static IP Address or DHCP Configuring for Network Interface Card (NIC)

By two ways we can set IP address for Network Interface Card.

      a) Dynamic IP Address - by using DHCP (Dynamic Host Configuration Protocol) server
      b) Static IP Address - by Setting a fix IP address for NIC.




Configuring DHCP Address for Network Interface Card (NIC)

Just edit the /etc/network/interfaces file to configure dynamic IP address for the network card.

susanta@admin:~$ sudo gedit /etc/network/interfaces

# auto lo
# iface lo inet loopback
auto eth0
iface eth0 inet dhcp

Here the IP address of the Network card will be collected from local DHCP server.

Now execute the following command to set IP address from DHCP server.


susanta@admin:~$ sudo /etc/init.d/networking restart
 * Reconfiguring network interfaces...                                                                                       Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:16:76:1e:6a:60
Sending on   LPF/eth0/00:16:76:1e:6a:60
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
................................
................................







Configuring Static IP Address for Network Interface Card (NIC)

Same way edit the /etc/network/interfaces file to configure static IP address for the network card.

susanta@admin:~$ sudo gedit /etc/network/interfaces

# auto lo
# iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.1.2
gateway 192.168.1.1
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255

Now restart the networking script file to set IP address for the Network Interface Card.

susanta@admin:~$ sudo /etc/init.d/networking restart

To check whether the new IP address is set for the network interface card, execute the following command,


susanta@admin:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:16:76:1e:6a:60
          inet addr:192.168.1.2   Bcast:192.168.1.255   Mask:255.255.255.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:21 Base address:0xde00

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:480 (480.0 B)  TX bytes:480 (480.0 B)

ppp0      Link encap:Point-to-Point Protocol
          inet addr:10.1.77.54  P-t-P:2.2.2.2  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:1585 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1744 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:553960 (553.9 KB)  TX bytes:792791 (792.7 KB)



Note: We can also set second IP address or virtual IP address for same network interface

susanta@admin:~$ sudo gedit /etc/network/interfaces

auto eth0
iface eth0 inet static
address 192.168.1.2
gateway 192.168.1.1
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255

auto eth0:1
iface eth0:1 inet static
address 192.168.1.3
gateway 192.168.1.1
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255 

Now execute the following command to check, whether it is working properly,

 

susanta@admin:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:16:76:1e:6a:60
          inet addr:192.168.1.2  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:21 Base address:0xde00

eth0:1    Link encap:Ethernet  HWaddr 00:16:76:1e:6a:60
          inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          Interrupt:21 Base address:0xde00

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:480 (480.0 B)  TX bytes:480 (480.0 B)