I recently had to switch from a DSL service because my home router broke and so I went to my cable TV company for high-speed Internet service. I bought an Arris SBG6900-AC wireless cable modem and now, no matter what I try, I cannot get my 5020L cameras to work. I go through the setup wizard and it always leads to a dead end.It says it cannot locate the cameras if I wire everything up according to the directions. The only time it detects a camera is if I attach the Ethernet cable from the camera to my laptop instead of to the modem. But that eventually leads to other failures in later steps (like when it asks me whether I want a wifi network or a WPS network). Is there something about my new modem or the cable Internet service that simply isn't compatible with these cameras? I called the tech help line and paid $40 but that got me nowhere. And the DLink email tech support doesn't seem to have a clue what's wrong. I think the WPS button may not work, but every other wireless device I have is working. I hate to throw out eight cameras.
WPS may or may not work, but that's because WPS is lousy, not because the cameras and Arris gateway are fundamentally incompatible. You main issue is discovering what IP address the gateway is assigning your camera. If you have that, you can log into the camera directly and configure it. Most gateways have an admin screen that will show what clients are connected to them, with the IP addresses assigned. With a camera connected to the Arris via a cable, have you tried logging into the gateway and looking for such a screen?
Also, depending on how you had your cameras configured on your old network, you may need use the hardware reset button on them to wipe them back to default settings in order to set them up again properly.