By default, the IP address 192.168.1.100 is used by Linksys routers. It is automatically assigned to the first device connected, via Ethernet or Wi-Fi, with the network. The default settings can be changed to any number of IP ranges by the router's system administrator.
It is common for IP addresses to be assigned by the router automatically or dynamically. When a new device is connected to the network, the router assigns it an address, generally the next available one in sequential order. Devices can also be assigned a static IP and automatically renew that IP address each time it is connected to the network.