Here’s the scenario: you are trying to fix a relative’s network issues and you need to access their router’s browser interface. We’ve all been there, fruitlessly pecking in combinations of 192.168.x.x. Unless you have every default router address tattooed on your forearm, you’ll eventually encounter one that stumps you.
When that happens, you can typically find the information with a simple command on Windows. Open the command prompt (Start > Run/Search for cmd) and then enter ipconfig. The address you need should be next to Default Gateway under your Local Area Connection, and it will often begin with 192.168.
Also see: The best routers reviewed and rated
If for some reason you can’t retrieve the router’s IP address using that method, we’ve compiled a brief list of popular router brands and their common default addresses. The list includes most router manufacturers with more than a dozen or so models, particularly if they deviate from the standard 192.168.1.1 address.
Default usernames and passwords
Likewise, if you’re looking for default usernames and passwords, RouterPasswords.com and PortForward.com should have you covered. Common default usernames include variations of admin (Admin, administrator, etc.), and the password is often admin, password, or simply left blank — needless to say, it’s good practice to change these during the initial setup.
Source Article from http://www.techspot.com/guides/287-default-router-ip-addresses/