Depending on your Internet Service Provider (ISP) you may be required to enter their login information into Portal before Portal can connect to the Internet. Your Portal LED will remain RED until these settings are updated. This is also known as PPPoE.
Log in to your Portal's web interface and click on "WAN IP". Turn on the settings for "My internet connection requires username and password" and enter the username, password, and service provider's name.
Click Apply. The settings will be saved and your Portal will attempt to connect online.