Configure network settings in linux via terminal

Applies to (Centos, Fedora, Red Hat Enterprise Linux 5)
Simple method:

# ifconfig eth0 192.168.10.12 netmask 255.255.255.0 broadcast 192.168.10.255

Or manually edit configuration files stored in /etc/sysconfig/network-scripts/

You can configure network card by editing text files stored in /etc/sysconfig/network-scripts/ directory. First change directory to /etc/sysconfig/network-scripts/:

# cd /etc/sysconfig/network-scripts/

You need to edit / create files as follows:

/etc/sysconfig/network-scripts/ifcfg-eth0 : First Ethernet card configuration file
/etc/sysconfig/network-scripts/ifcfg-eth1 : Second Ethernet card configuration file

To edit/create first NIC file, type command:

# vi ifcfg-eth0

Append/modify as follows:

# Intel Corporation 82573E Gigabit Ethernet Controller (Copper)
DEVICE=eth0
BOOTPROTO=static
DHCPCLASS=
HWADDR=00:30:48:56:A6:2E
IPADDR=10.10.29.66
NETMASK=255.255.255.192
ONBOOT=yes

Save and close the file. Define default gateway (router IP) and hostname in /etc/sysconfig//network file:

# vi /etc/sysconfig/network

Append/modify configuration as follows:

NETWORKING=yes
HOSTNAME=www1.nixcraft.in
GATEWAY=10.10.29.65

Save and close the file. Restart networking:

# /etc/init.d/network restart

Make sure you have correct DNS server defined in /etc/resolv.conf file:

# vi /etc/resolv.conf

Setup DNS Server as follows:

nameserver 10.0.80.11
nameserver 10.0.80.12
nameserver 202.67.222.222

Save and close the file. Now you can ping the gateway/other hosts:

$ ping 10.0.80.12

Output:

PING 10.0.80.12 (10.0.80.12) 56(84) bytes of data.
64 bytes from 10.0.80.12: icmp_seq=1 ttl=251 time=0.972 ms
64 bytes from 10.0.80.12: icmp_seq=2 ttl=251 time=1.11 ms

Change HOSTNAME

Step # 1:
You need to update two files: