If the Connection is DSL make the model as bridge method and configure it.
Highly recommended is the directly terminated from tower advise to put 4-port or 2-port switch before firewall wan connection
Step 1 : Login to the Tacitine. (If you are configuring the Tacitine for the first time, the default Lan IP is http://192.168.100.1) and default username : admin & Password : admin99
Step 2 : Click the Configuration > Network Setting tab.
Step 3 : Click WAN1 for the WAN interface (WAN1 by default.)
Step 4 : In Wan connection method > select PPPoE and mention the user name and password provide by ISP