Diagnostics and Troubleshooting 
159
 AC1900, N900, and N450 WiFi Cable Data Gateways
Internet LED or Online LED Is Off
If the Internet LED (or, for model AC1900, the Online LED) is off, the cable data gateway was 
unable to connect to the Internet. Verify the following:
• Check that the Internet information is correct (see Manage the Internet Setup on 
page  42).
• Check to see if your cable service provider is experiencing a service problem. It might not 
be that the cable data gateway cannot connect to the Internet, but rather that your cable 
service provider cannot provide an Internet connection.
Obtain an Internet IP Address
If your cable data gateway cannot access the Internet and your Internet LED lights green, 
see if the cable data gateway can obtain an Internet IP address from the cable service 
provider. Unless you were assigned a static IP address, your cable data gateway requests an 
IP address from the cable service provider. You can determine whether the request was 
successful using the web management interface.
 To check the Internet IP address:
1.  On your computer, launch an Internet browser such as Mozilla Firefox or Microsoft 
Internet Explorer. 
2.  In the address field of your browser, enter http://routerlogin.net.
You are prompted to enter a user name and password.
3.  Type admin for the user name and type your password.
If you did not yet personalize your password, type password for the password.
4.  Click the OK button. 
The BASIC Home screen displays.
5.  Select ADVANCED > ADVANCED Home. 
The ADVANCED Home screen displays.
6.  In the Internet Port pane, check that an IP address is shown in the IP address/Mask field.
If 0.0.0.0 is shown, the cable data gateway did not obtain an IP address from the cable 
service provider.
If the cable data gateway cannot obtain an IP address from the cable service provider, the 
cable service provider might check for a host name, a domain name, or both. 
Assign the host name, domain name, or both. For more information, see Manage the Internet 
Setup on page  42.