What is is a Private IP Address, which is used by many router/modem manufacturers to identify their device on a network. The manufacturers fabricate this private IP Address in the firmware of their devices. The user can enter this private IP Address in the address bar of the web browser running on a computer connected with the device.

Some of the manufacturers also allow the user to change the IP Address as per their convenience.

What is a Private Network and Private IP Address

Early network design, when global end-to-end connectivity was envisioned for communications with all Internet hosts, intended that IP addresses be uniquely assigned to a particular computer or device. However, it was found that this was not always necessary as private networks developed and public address space needed to be conserved.

Computers not connected to the Internet, such as factory machines, routers and other networking rquipments that communicate only with each other via TCP/IP, need not have globally-unique IP addresses. Three ranges of IPv4 addresses for private networks have been reserved. These addresses are not routed on the Internet and thus their use need not be coordinated with an IP address registry.

Today, when needed, such private networks typically connect to the Internet through network address translation (NAT).

IANA-reserved private IPv4 network ranges
Start End No. of addresses
24-bit Block (/8 prefix, 1 × A) 16777216
20-bit Block (/12 prefix, 16 × B) 1048576
16-bit Block (/16 prefix, 256 × C) 65536

. Router Login and Password Details

Given below is a list of some of the most common routers and modems alongwith their default IP Addresses, usernames and passwords. If your router manufacturer is using one of the given IP Addresses, then you can use the username and password to access the device and change the settings.