====== IP Address ======

===== Temporary =====
  * Use ifconfig command:
<code>
# ifconfig eth0 192.168.1.5 netmask 255.255.255.0 up
</code>

===== Permanent =====
  * Find the configuration file corresponding to the NIC for which you want to set a static IP and edit it.
<code>
# cd /etc/sysconfig/networking/devices
# vi ifcfg-eth0
</code>

  * Now set the parameters below according to your settings
<code>
DEVICE=eth0
BOOTPROTO=none
HWADDR=00:0C:29:DE:94:8B
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes
NETMASK=255.255.255.0
IPADDR=192.168.0.100
GATEWAY=192.168.0.1
</code>

  * To set the nameservers, change directory to /etc and edit resolv.conf.
<code>
# cd /etc
# vi resolv.conf
</code>

  * The file format should be like this:
<code>
search your-dns-search-path
nameserver dns1-ip-address
nameserver dns2-ip-address
nameserver dns3-ip-address
</code>

  * Now save the configuration file and exit the text editor. To apply changes, we need to bring the network interface down and back up.
<code>
# ifdown eth0
# ifup eth0
</code>

====== Redhat 7.X ======

===== ifconfig =====

The minimal install does not include ifconfig. To install ifconfig run the following:

<code>
yum install net-tools
</code>

===== EnsXXX =====

In Redhat 7.X, the interface naming convention has changed from ethX to EnsXXX. To restore the default behavior, do the following:

  - Edit /etc/default/grub to add the lines to the kernel paramaters:

<code>
GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"
</code>

  - grub2-mkconfig -o /boot/grub2/grub.cfg
  - Rename /etc/sysconfig/network-scripts/ifcfg-enXXX to ifcfg-eth0
  - Set Name=eth0 and Device=eth0 in /etc/sysconfig/network-scripts/ifcfg-eth0
  - reboot