System Architecture: All/General
RedHat Release: All/General
FAQ Category: Networking and netcfg
Modification Date: Oct 2, 1998
How do I configure a network card to have multiple IP addresses?
[Note, this assumes you already have the network card working with one IP address. If not, do that before you continue.] The easiest way to configure a network card for IP "aliasing" is to login as root and cd to /etc/sysconfig/network-scripts if you do an 'ls' you see one or more files that start with: ifcfg- Let's say you have an existing ethernet card (eth0) with an IP of 192.168.1.1 and you want to alias 192.168.1.111 to it as well. First copy the ifcfg-eth0 file to ifcfg-eth0:0 Next edit ifcfg-eth0:0 with your favorite editor. Edit the fields as appropriate. DEVICE=eth0 --> DEVICE=eth0:0 USRCTL=??? (Allow regular users to control this interface?? yes/no) ONBOOT=??? (Turn this interface on at boot time?? yes/no) BOOTPROTO=none BROADCAST=192.168.1.255 (the brodcast of the new network) NETWORk=192.168.1.0 (the network the new IP address lives on) NETMASK=255.255.255.0 (the network mask of the network) IPADDR=192.168.1.1 --> IPADDR=192.168.1.111 (the 2nd IP address of the interface) Save the file, and test your work: ifup eth0:0 ifconfig You should now see the interface eth0:0 "UP" You can do this as many times as you wish, by incrementing the second number. For example a second alias would be interface eth0:1 and so on.
man ifconfig