Assigning a virtual IP to a NIC

Assigning a virtual IP to a NIC is a very easy task either you use the system-config-network tool or just do some text file editing. The script ifconfig can also be used to create a virtual network interface, but this would not be permanent since the changes ifconfig makes do not survive a reboot.

In Fedora, all information about the network interfaces is kept in the following directories:

• /etc/sysconfig/network-scripts/


• /etc/sysconfig/networking/

My NIC configuration script is /etc/sysconfig/network-scripts/ifcfg-eth0 looks like this:

DEVICE=eth0

BOOTPROTO=static

BROADCAST=192.168.0.255

HWADDR=00:00:00:00:00:00

IPADDR=192.168.0.1

NETMASK=255.255.255.0

NETWORK=192.168.0.0

ONBOOT=yes

TYPE=Ethernet

GATEWAY=192.168.0.254

Make a copy of this in the same directory naming the new file ifcfg-eth0:1

# cp ifcfg-eth0 ifcfg-eth0\:1

Modification in file ifcfg-eth0\:1 is shown in bold

DEVICE=eth0:1

BOOTPROTO=static

BROADCAST=192.168.0.255

HWADDR=00:00:00:00:00:00

IPADDR=192.168.0.101

NETMASK=255.255.255.0

NETWORK=192.168.0.0

ONBOOT=yes

TYPE=Ethernet

GATEWAY=192.168.0.254

So, its IP address will be 192.168.0.101. Save the file and copy it to/etc/sysconfig/networking/devices/:

# cp ifcfg-eth0\:1 /etc/sysconfig/networking/devices/

Also, copy it to your default network profile or whichever profile you use:

# cp ifcfg-eth0\:1 /etc/sysconfig/networking/profiles/default/

Now, bring up the new interface using the ifup script:

# ifup eth0\:1

Running ifconfig, the new interface should be listed. You can also check it by pinging:

# ping 192.168.0.101