Redhat IP Configuration The IP configurations on the Redhat distribution of the Linux operating system are stored in the directory /etc/sysconfig/network-scripts/. Each interface, as well as sub-interface, requires a unique configuration file. The below example assigns the interface eth0 an IP address of 192.168.1.42 on a class C network with 192.168.1.1 as the gateway. /etc/sysconfig/network-scripts/ifcfg-eth0: DEVICE=eth0 IPADDR=192.168.1.42 NETMASK=255.255.255.0 ONBOOT=yes GATEWAY=192.168.1.1 In order to assign multiple IP addresses on the same interface (eth0), there must be a configuration file for the sub-interface eth0:0 (incrementing as necessary). The below example will add three more IP addresses to the same interface: /etc/sysconfig/network-scripts/ifcfg-eth0:0: DEVICE=eth0:0 IPADDR=192.168.1.41 NETMASK=255.255.255.0 ONBOOT=yes /etc/sysconfig/network-scripts/ifcfg-eth0:1: DEVICE=eth0:1 IPADDR=192.168.1.44 NETMASK=255.255.255.0 ONBOOT=yes /etc/sysconfig/network-scripts/ifcfg-eth0:2: DEVICE=eth0:2 IPADDR=192.168.1.45 NETMASK=255.255.255.0 ONBOOT=yes Note that a gateway statement is not necessary in this file because the same gateway was defined in /etc/sysconfig/network-scripts/ifcfg-eth0. To update your system's IP configuration after making changes to the /etc/sysconfig/network-scripts/ directory, execute # service network restart