Have you ever unboxed your brand-new router, hooked it up to your existing cable modem and nothing happens?  The awesome new device you just purchased doesn’t go online and the internet light stay amber or red.  Believe it or not this is actually a common issue referred to as MAC Binding.  Essentially what is happening is the Modem is still bound to the MAC (media access control) address from the last device that was connected to it.  When the modem looks to hand out the public address from your ISP it does not recognize the address being offered so it does not give out the IP address.  Its like trying cash a check without ID, no verification so doesn’t work. 

So how do we fix this?  Well, that’s very simply really.  Frist you will want to unplug the power cable and the coaxial cable from the back of the modem. Next connect your router to the modem via ethernet, but please make sure the ethernet cable is in the WAN port on your router.  Then reconnect the power cable and power on your modem but leave the coaxial disconnected.  Wait 3 to 5 minutes to give the modem enough time to flush its memory, then reconnect the coaxial cable.  Once the modem fully connects to the internet, check the router’s internet light it should now be good.  For TP-Link routers this means either White, Green or Blue depending on your model.  Check the internet and see if you can now reach your favorite websites.  In rare cases you may need to contact your ISP and have them clear the modem’s connection remotely.