Troubleshooting a PPPoE Authentication Failure on SonicWall Firewall (UTM) Appliances
A PPPoE authentication failure error message means that either the username and/or password entered into the WAN interface settings page is incorrect.
In firmware 6.x, this page is found under General > Network.
In SonicOS Standard, WAN settings are located under Network > Settings.
In SonicOS Enhanced, select Network > Interfaces, then click the Configure icon for the WAN (AKA X1) interface.
Check the following troubleshooting items:
Verify the correct username and password are entered.
Check the entries in the SonicWall against the information supplied by your Internet service provider. If you still have a PPPoE client installed on a PC that was connected directly to the ISP, check its settings to verify the username and password.
Determine whether you need a domain name as part of the username. Some ISPs require that the username entered includes their domain name (e.g. firstname.lastname@example.org).
Remember that the username and password are case-sensitive.