If you have a modem, it may lock the mac address of the router.

So when you change the router and if the router cannot get IP address via dhcp, you can do either of the following.

  1. Reboot the modem. Or if immediatelly does not solve, turn off the modem for a longer time, e.g. 30 minutes then turn it on.
  2. Clone the old router’s mac address to the new router.
  3. Just call your ISP customer service to reset the modem