Ubuntu 11.10 Virtual NIC IP Workaround

The normal way of adding virtual nic ip is by setting it in /etc/network/interfaces, like the following:

auto eth0:0
iface eth0:0 inet static
address 192.168.0.111
netmask 255.255.255.0
broadcast 192.168.0.255
gateway 192.168.0.1

Unfortunately, there is a known bug which prevent such configuration to work. Take a look here.

The first workaround that I figured out is by using /etc/rc.local script.

Add the following lines before exit(0) inside that script:

#################################

sleep 4  # This due to concurrency, set some delay in order for the networking to be set up properly first

ifconfig eth0:0 192.168.0.111 netmask 255.255.255.0 broadcast 192.168.0.255

# or use below command to replace above ifconfig command

# ip addr add 192.168.0.111 dev eth0

#################################

The second workaround is, IMHO, better. No sleep hack necessary, since upstart script is used instead of rc.local script.

Create /etc/init/network-interface-virtual.conf (or use different name as you like), with the following lines inside:

#################################

description "configure virtual network device"

respawn

console none

start on (net-device-up IFACE=eth0)

stop on runlevel [!12345]

script

exec ip addr add 192.168.0.111 dev eth0

# or use ifconfig command below

# ifconfig eth0:0 192.168.0.111 netmask 255.255.255.0 broadcast 192.168.0.255

end script

#################################

Reboot your system if necessary and everything is set and the virtual nic ip is ready to use. Oh, one more thing. There is also a bug (I think), which makes the virtual nic ip not showing with the ifconfig -a command. Just ping the virtual ip address to test whether it's up or not.