I just had to replace my AT&T router with a "new" one. They upgraded by 2011 router with a 2014 router. I decided to be very careful knowing the issues I had in the past. I have lights, switches, fans, thermostats, speakers, doorbells all on wifi and was successful. Process was simple and took ~ 1/2 hour.
- gather the WiFi SSID, Password, Security, and Encryption methods from the existing router.
- replace the router per the instructions provided.
- log onto the new router and go to page for wifi configuration
- program the wifi channels on the new router to have the same SSID, Password, Security, and Encryption method as the old router.
- save changes (as necessary).
- go to the status page and look for the hubitat in active device. The IP address here is the new hubitat IP address.
- wait. All devices should reconnect to internet w/o intervention (mine did).
- check all devices. Chances are at least one will not carry over for some reason. Correct these before proceeding.
- in Hubitat, update IP addresses either manually (static IP address devices) or automatically by running the installation app (forcing discovery and IP update).