192.168.1.254 IP address is used a a default address by various brand of routers. Below are routers which use 192.168.1.254 as a default address:
2Wire, Aztech, Billion, D-Link
Gigabyte, Linksys, Motorola, MSI, Netopia, Planet
Siemens, Sitecom, SpeedTouch, Thomson, Trendnet, ZTE
This IP address is preset by router manufacturer at the factory but you can always change it in a router administration interface.
To access router administration interface you need to type http://192.168.1.254 in your web browser. You will see a prompt for username and password for your router.
If you don't see router administration interface at http://192.168.1.254/ then most probably your router is configured to use a different IP address. You can check instructions on home page of this website to get IP address of your router on different operating systems. Also if you use Wi-Fi network to connect to the router or modem try switching to wired connection to make sure that you connected to a right network and there are no issues with connectivity.
If you don't remember password for you router you can try following default combinations which are used by router manufacturer as defaults.
All D-Link routers use username: admin
D-Link DI-514 and DI-524, DI-804, DI-604, DI-704, use empty password.
All other D-Link routers use password: admin