How can I configure a static IP v4 address?

Environment

• Red Hat Enterprise Linux 4
• Red Hat Enterprise Linux 5
• Red Hat Enterprise Linux 6

Issue

• I would like to configure a static IP address on my RHEL server.

Resolution

For RHEL 7 with NetworkManager, please see How to configure IP addressing with NetworkManager (nmcli) in RHEL 7

• Create an ifcfg file in the /etc/sysconfig/network-scripts/ directory for the interface. Assuming the interface is named eth0, set the IP address and netmask as needed:

  $ cat /etc/sysconfig/network-scripts/ifcfg-eth0
  DEVICE=eth0
  ONBOOT=yes
  BOOTPROTO=none
  IPADDR=
  NETMASK=
  # *** HWADDR is only required for RHEL 5 and below ***
  # HWADDR=
  #
  # Other optional parameters:
  # GATEWAY=
  # DNS1=
  # DNS2=
  # DOMAIN=
  

• Once the configuration file has been defined, it can be activated with the ifup command:

  # ifup eth0
  

Diagnostic Steps

• If needed, the MAC address (HWADDR) can be found with the ip link command:

  $ ip link show eth0
  2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
      link/ether 1c:c1:de:ee:4e:e8 brd ff:ff:ff:ff:ff:ff
                         ^
                    MAC address
  

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