When you replace a router that is connected to an already installed modem, your new router might not be able to connect to the Internet even if your old router connected without issue. The most common cause for this problem is called media access control (MAC) binding.
With MAC binding, your modem or Internet Service Provider (ISP) stores your old router's unique MAC address for authentication purposes. Your modem or ISP does not recognize your new router's MAC address and might deny access to the Internet.
For more information about MAC addresses, see What is a media access control (MAC) address?.
To resolve this issue, your modem or ISP must store your new router's MAC address in place of your old router's MAC address. You can prompt your modem or ISP to check for a new MAC address using any of the following methods:
- Reboot or factory default your modem. For more information, see your modem's documentation.
- Power off your modem and router, then power on your modem and wait five to ten minutes. Next, power on your router and wait until the Internet LED lights solidly.
- Disconnect all of the cables from your modem except the power cable, wait ten to twenty minutes, then reattach the cables.