Ubuntu Linux: Creating ethernet alias for eth0 network device

 how to create alias for eth0 so that I can have multiple IP address?

To create alias for eth0 use ifconfig command. 
It is use to configure a network interface and aliases.

Assuming that your eth0 IP is 192.168.1.10 
and you would like to create an alias eth0:0
with IP 192.168.1.11.
Type the following command:

#sudo ifconfig eth0:0 192.168.1.11 up

or

#sudo /sbin/ifconfig eth0:0 192.168.1.11 up

Verify that alias is up and running using following two command(s):

#/sbin/ifconfig
#ping 192.168.1.11
#ping your-getway-ip

 

Permanent configuration

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:

#sudo nano /etc/network/interfaces

on Debian as root:

# nano /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

Please note that you can also use graphical tools located at  
System > Administration > Networking menu. 
Or use the following GUI tool to setup aliases, hostname, dns settings etc:

#sudo network-admin

If you want more network aliases, use eth0:1, eth0:2, eth0:N (max upto 254).

#Perfect Server Setup