192.168.1.1 is a default private IP address used by some NAT/network devices such as routers. These IP addresses were devised in order to resolve the shortage of IP addresses to be used on the Internet. The private IP address ranges have been defined by RFC 1918.
What are Private IP Addresses?
An IP address (IP stands for Internet Protocol), is a numeric identification that is assigned to any device that is part of a computer network. Each machine or device in a network should have a unique IP address. These addresses are numeric addresses and are divided into four parts, that are separated by dots. An example of an IP address that you will see a lot is 192.168.1.1.
One set of these numbers is classed as private IP addresses. This set of numbers range from 192.168.0.0 to 192.168.255.255. These numbers are reserved and are unique compared to other IP addresses. These numbers are only unique within the network they belong. For instance, one computer could be assigned an address as 192.168.1.1 in your school’s network and another computer can have exactly the same address in your home network and it won’t cause any problem.
These numbers are described as being private, given the fact that they can't be used to identify your computer outside of your own network or the Internet. This state of private IP addresses is called being non-routable. For your computer to be identified on the Internet you need to use a Network Address Translator, which is called NAT for short.
NAT and Private Address Space
There started to be a shortage of IP addresses simply due to the method through which these addresses are allocated. NAT devices were used as a quick fix for this shortage. For instance, let’s assume that you have four computers at home that connect to the Internet. Each computer in your private network will have its own assigned private IP address. Each computer will be connected to a router that will then in turn connect to the Internet.
The NAT device, such as a router in your home or the firewall in your office, will modify the information that your computers send to the Internet so they will get a normal address that can be used on the web. The NAT device is also responsible to route the information entering the network to the correct computer in your private network.
192.168.1.1 Default Private IP Address
192.168.1.1 is one of the default addresses used by NAT devices in private networks. Other defaults include 192.168.2.1 and 192.168.0.1. These have been defined by RFC 1918, which are working notes on Internet research and development. The Internet Assigned Numbers Authority has reserved these and other numbers within their respective ranges for private network use.
Many NAT devices or network devices use 192.168.1.1 as a default private IP address. Popular brands that use this and the other default numbers include Linksys and Speedtouch.