The IP address 192.168.1.1 is the default for Linksys brand home broadband routers. This address is set by the manufacturer at the factory, but you can change it at any time using the network router's administrative console.
192.168.1.1 is a private IPv4 network address. Any brand of network router, or any computer on a local network for that matter, can be set to use this address. As with any IP address, however, only one device on the network should use 192.168.1.1 to avoid address conflicts.