Problem – Sonicwall TZ-100 will not connect to AT&T DSL or any DSL using PPPoE.
Solution – After configuring the WAN Interface for PPPoE, click OK, do not click connect under the Interface screen. Simply go to System, select restart on the Sonicwall. When it comes back up it will connect immediately. There seems to be an issue where it needs to restart but the sonicwall doesn’t indicate or suggest that. I have verified this with Sonicwall support.
Notes – This assumes you have your DSL modem configured correctly in bridge mode.