I recently upgraded to at&t gigabit internet from a 24 plan. This required me upgrade my current modem. I use quite a bit of port-forwarding for things like plex, lab servers, etc. and had a bit if difficulty getting the new modem to pass all of the traffic to my Orbi so that the Orbi can forward the traffic to the correct hosts.
Here are the steps I took in order to get everything working.
- Netgear Orbi RBR50 + 2 RBS50 satellites
- ARRIS BGW210-700 Modem/Router aka at&t modem
WAN <= at&t model <= Orbi Star Network <= LAN
The at&t modem has a default local address space that conflicts with the Orbi's (192.168.1.0/24). If you plug the Orbi into the router, the Orbi will detect this and change its own address space to 10.0.0.0/24. If this is ok with you, please proceed. However I had a lot of static IPs on 192.168.1.0/24 so I opted to change the at&t modem address space to 192.168.0.0/24.
If your Orbi changed its subnet to 10.0.0.0/24. Go into the Orbi and change it back.
Now make sure the Orbi is plugged into the at&t modem and then set up IP Passthrough in DHCPS-Fixed mode selecting your Orbi router as the device. This will assign the Orbi router the public IP address of the at&t modem
Now log into your Orbi and reboot it.
Once your Orbi is back up the IP Address listed in the INTERNET PORT should no longer be on the 192.168.1.0/24 or 10.0.0.0/24 subnet. If it is you will need to release and renew the INTERNET PORT IP address by clicking the CONNECTION STATUS button which will open a new window where you can RELEASE the IP and then RENEW it. The address should now be the same as the at&t router and port forwarding should work.