Netgeat cm1200 lan port not working but lights are on

[Ehhwa09]

So I’ve done a hard reset with my isp and everything. Nothing is working. But I noticed that the lan 3 port is flashing but not functioning as in giving internet to the router.

[FURRYe38]

Use only port #1 on the CM modem. 

The CM modem is not a router, only a modem.