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 on a class C network with as the gateway. /etc/sysconfig/network-scripts/ifcfg-eth0: DEVICE=eth0 IPADDR= NETMASK= ONBOOT=yes GATEWAY= 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= NETMASK= ONBOOT=yes /etc/sysconfig/network-scripts/ifcfg-eth0:1: DEVICE=eth0:1 IPADDR= NETMASK= ONBOOT=yes /etc/sysconfig/network-scripts/ifcfg-eth0:2: DEVICE=eth0:2 IPADDR= NETMASK= 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