Welcome to CH.
Are you now using DSL? What did you have before?
One provider puts it this way:
Using the provided Ethernet cable, connect the modem ton the WAN of your wireless router. Both the modem and ant router must be off. You rcomputer should be connected to one of the LAN ports of the router. Then computer also should be in the power off state.
Next turn on the power in this order:
1. Turn on the modem, wait 30 seconds.
2. Turn of the router and wait 30 seconds.
3. Last turn on your computer and let it do the normal start-up. This may take two minutes for some computers.
Talking with the support people, this has to be done one time for the modem to 'learn' what kind of router your have.
Have you asked your support people?