Router manufacturers assign routers a default private IP address. The address 192.168.0.100 is not a common router address. Still, a few broadband router models and access points use it (as well as other devices), including some Netgear models and some printers by SerComm and USRobotics, among others.
How Private IP Addresses Work
Private network IP addresses cannot be accessed from the internet directly but can allow any device on a local network to connect to another device on that network. The Internet Assigned Numbers Authority (IANA) manages IP addresses and has reserved certain number blocks to be private. These are:
10.0.0.0 to 10.255.255.255 172.16.0.0 to 172.31.255.255 192.168.0.0 to 192.168.255.255
Private IP addresses cannot be used by any website or device on the internet or a local network. For example, a ping to a private address only works if generated by another device within the local network. It doesn’t work if attempted from outside the network. For this reason, private IP addresses do not need to be unique except within their local network.
Configure 192.168.0.100 in the Router Administrative Console
Private IP addresses are managed through the router’s administrative console. To configure your router or another device, including changing its default IP address or assigning a specific address to a device on your network, open a web browser and enter its IP address in the URL address bar. A common router IP address is 192.168.1.1, although your router’s vendor specifies the console’s address. Routers ship with a default username and password credentials. Usernames are usually admin or user, while passwords might be admin, user, or 1234. Some devices ship without a default username and password, so you can access the console by clicking through the login dialog.
Find Your Device’s IP Address
Your device’s IP address is usually printed on the box or on the bottom of the device. If you can’t find it, you can access it from your computer. To find your router’s default IP address, use the Windows ipconfig utility:
Automatic Address Assignment of 192.168.0.100
A common use of the address 192.168.0.100 is a router automatically assigning it to a device on its network. For example, administrators sometimes configure routers that have 192.168.0.1 as the default address to use 192.168.0.100 as the starting address of their DHCP range. This setting enables the first device on the network to get an address that ends in an easier-to-remember round number (100) rather than the next address in the sequence (2). Alternatively, administrators sometimes configure the router’s client IP range as 192.168.0.2 to 192.168.0.99, leaving 192.168.0.100 available for static IP address assignment.
Avoid IP Address Conflicts
Avoid manually assigning this address or any address that belongs to a router’s DHCP address range. Otherwise, IP address conflicts may result as the router may assign an address that is being used. Check the router’s console settings to determine the DHCP pool it defined. Routers define this range using a combination of several settings, including:
Network mask: The router’s subnet defines the minimum and maximum private IP address allowed. Start address: The beginning number of the range (used to further limit within the subnet). Maximum number of clients: An additional limit some routers enforce in addition to the mask.
