Private IP addresses are non-internet facing internet protocol addresses on the internal network. These addresses are given by network devices like routers. In general, private IP addressing utilizes the addresses from class c range that is reserved for NAT. Routers can assign these addresses using DHCP or set it manually. Later, these addresses will communicate with one another via the router. A private IP address can be guaranteed exclusive to internet network for avoiding address conflicts. If a computer which is connected to the router direct does not have on static IP address, assigning a private address manually cannot enable communication. This type of IP addresses cannot be contacted over the web as a device with a public address can. Thus, it affords an additional security layer to the users.
Uses of private IP addresses
Internet assigned number authority or IANA has reserved certain internet protocol addresses as private ones for use with intranets and internal websites. These IP addresses are also known as RFC 1918 IP addresses that cannot be routed on the public network. They are meant for computers behind the router and other NAT device. Private addresses can also be used to hide computer systems from the public or open internet and to give an extra range of addresses for organizations that lacks sufficient public addresses for distributing on the network. If a person connects to the internet like a home user with the residential router, he will benefit from this type of arrangement. Even though he may be investing for one address via his internet service provider, he can have any number of devices connected to his router. Using the private addresses can make computers invisible to certain kinds of network attacks. Here are the uses of private IP addresses.
- For people who did not register their computers or devices with DHCP service, the local area network assigns internal IP addresses so that they can have enough connectivity for reaching the DHCP registration webpage.
- For servers like database or backup server that have to communicate with local servers, private IP addresses let server to server communication over the private network. Even computers on IU network cannot access these private networks.
- For computers with no requirement of internet connectivity like print servers, file servers and printers, the private addresses let them communicate with other systems on IU campus network as well as remote computers linked to VPN.
It is very vital that private IP addresses used within a company do not lead to address conflicts. Since the locally connected servers can use back nets, the private addresses used for different back nets are same, but they cannot make conflicts with other IP addresses on the campus.
How private addresses differs from public IP addresses
Public addresses are assigned to the computing device and provide direct access to the users over the internet. An email server, web server or any other server device accessible from the LAN are candidate for using a public IP address. Public IP addresses are globally unique and they can be assigned to unique devices.
Private addresses are space allocated for organizations and companies to create their private network. 1 class A, 1 class C and 1 class B are three IP blocks which are reserved for private uses. Smartphones, tablets and computers sitting behind the home and personal computers with companies are using these assigned private addresses. For example, a printer residing in the home is given a private IP address so that the family members can only print to their local printer. When a computer or laptop is assigned an address, the local computers see this system through its private address. However, computers and devices residing outside the local network cannot communicate through the private address, but uses the public IP address of the router to communicate. A NAT or network address translator must be used for allowing direct access to the local device assigned to a private address.
Private internet protocol addresses are used on business and residential computers to improve the network security as well as for conserving the public addressing space. An address is considered private only if it falls with any of the following IP ranges that are reserved for private users. The private IP ranges are
- 0.0.0 to 10.255.255.255
- 254.0.0 to 169.254.255.255
- 16.0.0 to 172.31.255.255
- 168.0.0 to 192.168.255.255
192.168.1.1 comes under the range of private IP addresses. This address is used by several hardware manufacturers. This address is a part of default factory settings, but this address can be changed according to the user’s preference.
10.0.0.1 is another private IP address which is used as the default address by several network routers such as Cisco router models. This address can be used many times and even it can be used by several users who are in different networks.