If you have been given your own private subnet (we still say /29) from your hosting provider and have 5 websites that need their own dedicated IP address. You will be able to add sub-interfaces onto a single NIC (network interface card), and assign each sub-interface with its own dedicated IP address from the subnet.
You will need to be either root or have an user with sudo privileges
1. Edit the interfaces file within the network folder
sudo nano /etc/network/interfaces
2. Add the additional IP addresses under eth0
# The primary network interface 10.10.10.10 - 14 are usable IP addresses auto eth0 iface eth0 inet static address 10.10.10.10 netmask 255.255.255.248 gateway 10.10.10.9 # The Rest of the IP addresses in the /29 auto eth0:1 iface eth0:1 inet static address 10.10.10.11 netmask 255.255.255.248 gateway 10.10.10.9 auto eth0:2 iface eth0:2 inet static address 10.10.10.12 netmask 255.255.255.248 gateway 10.10.10.9
3. Restart the network daemon
sudo /etc/init.d/networking restart
4. Enable the new sub-interface
sudo ifup eth0:1
This will create a NIC alias and therefore allow you add additional IP addresses. This can be done for up to 254 IP addresses