For a small number of additional addresses: in /etc/sysconfig/network-scripts/ , copy ifcfg-eth0 (or whichever interface you want) to, e.g., ifcfg-eth0:0 . Then in ifcfg-eth0:0 , just replace each instance of "eth0" with "eth0:0", and set the IP address to the one you want to add. After saving ifcfg-eth0:0 , do either: ifup eth0:0 or service network restart or reboot the machine, if you want to be sure it works after reboot. For a large number of sequential IP addresses: create /etc/sysconfig/network-scripts/ifcfg-eth0-range0 containing: ---- IPADDR_START=192.168.0.101 IPADDR_END=192.168.0.120 NETMASK=255.255.255.255 CLONENUM_START=3 NO_ALIASROUTING=yes ---- IPADDR_START is the address, from which your IP range is starting. IPADDR_END is the address, by which your IP range is ending. CLONENUM_START is the number of virtual device the first IP address will be assigned to. In the above example, applying configuration changes will make IP address 192.168.0.101 to be mapped to eth0:3 virtual device, 192.168.0.102 to eth0:4, etc. you can create several ranges for the same interface, so long as CLONENUM START values do not overlap.