Your ethernet configuration is located in a file called /etc/network/interfaces. If you reboot system you will lost your alias. To make it permanent you need to add it network configuration file:
gksudo gedit /etc/network/interfaces
OR
sudo vi /etc/network/interfaces
Append the following configuration:
auto eth0:0
iface eth0:0 inet static
name Ethernet alias LAN card
address 192.168.1.11
netmask 255.255.255.0
broadcast 192.168.1.255
network 192.168.1.0
Save the file and restart system or restart the network:
sudo /etc/init.d/networking restart
ref: http://www.cyberciti.biz/tips/ubuntu-linux-creating-ethernet-alias-for-eth0-network-device.html