Cheat Sheet: Static IP Adressing - the Debian, Redhat and FreeBSD way

Quick and dirty way to properly set a static IP address on various UNIX-like systems.

Debian Based Systems

Tested on: Ubuntu 12.04

Edit /etc/network/interfaces. The dns-* entries are needed if using resolvconf. 

auto eth0
iface eth0 inet static
    address 172.20.88.100
    netmask 255.255.255.0
    network 172.20.88.0
    broadcast 172.20.88.255
    gateway 172.20.88.1

dns-nameservers 10.0.0.53 10.0.1.53 8.8.8.8
dns-search blakhole-networks.com
dns-domain blakhole-networks.com
Restart the networking service using sudo /etc/init.d/networking restart or just reboot to take effect.

FreeBSD

Tested on: FreeBSD 6,7,8,9

Edit /etc/rc.conf and add lines in for each interface that needs static addressing. The following example addes IPv4 and IPv6 addresses to the em0 and em1 interfaces. 

ifconfig_em0=" inet 172.20.1.5 netmask 0xffffff00"
ifconfig_em0_ipv6=" inet6 fd69:dead:d00d:10::5 prefixlen 64"
ifconfig_em1=" inet 172.20.5.5 netmask 0xffffff00 mtu 8192"
ifconfig_em1_ipv6=" inet6 fd69:dead:d00d:5::5 prefixlen 64"

defaultrouter="172.20.1.1"
ipv6_defaultrouter="fd69:dead:d00d:10::1"

Restart by running /etc/rc.d/netif restart as root.

Redhat Based Systems

Tested on: CentOS 6, Fedora 18

Change directory to /etc/sysconfig/network-scripts/ and edit the ifcfg- file for each network interface to be configured. The following example is for the eth0 interface, and adds IPv4 and IPv6 addresses: 

DEVICE="eth0"
BOOTPROTO="static"
DNS1="127.0.0.1"
GATEWAY="10.0.0.1"
HWADDR="00:16:3E:00:18:1A"
IPADDR="10.0.0.53"
NETMASK="255.255.255.0"
BROADCAST="10.0.0.255"
IPV6INIT="yes"
IPV6_AUTOCONF="yes"
IPV6ADDR="fd69:dead:d00d:0053::53"
IPV6ADDR_SECONDARIES="2001:470:9995:53::53"
IPV6_DEFAULTGW="fd69:dead:d00d:0053::1"
NM_CONTROLLED="no"
ONBOOT="yes"
Changes take effect by running service network restart as root.