Hi, I'm going through a similar setup. Interestingly enough, I'm using an old Belkin as a modem to a Netgear Nighthawk R7000. I've got the setup to work by enabling "Modem only" mode, but how did you avoid the double NAT problem?
Also, besides switching "Modem only" mode and disabling everything in the Wireless section of the Belkin, do you make any other configurations?
I've spent roughly 6 hours trying to get an old Belkin router in Modem Only mode to connect to my new Nighthawk R7000 router. Any help would be greatly appreciated.
I've set up the Belkin F5D9630-4A in modem only mode (nearly everything disabled). Connected the LAN 1 on the Belkin to the internet port on the Netgear. Configured the Netgear with Username and Password from EE and then input the Internet IP Address from the modem and the DNS addresses (one possibly strange thing to note - once I put the Belkin into Modem Only mode, the DNS Primary and Secondary are now the same as the IP Address).
I'm only getting an orange Internet light on the Netgear with no access to the internet.
I also have an EE Brightbox. I've successfully set this up with the Netgear by disabling UPNP - DHCP - Firewall etc. but this creates a double NAT causing Xbox's to have an NAT of strict.
I could really do with getting the Belkin to work in modem only mode ideally. I just can't figure out how it's done.
Any help would be great!