Dual WAN with internal 5G Modem and Starlink

Hello,

I have the M2M H721 5G modem/router. The unit is stellar and does generally everything I want, until now. The unit also goes by UniElec U7621-06 or MediaTek MT7621.

What I am trying to do is use the 5G modem as a primary unit, with Starlink as failover... or to have both running at the same time and load balance because I pay for both so I might as well get the full use of both.

Either way, I am running into the issue of Double WAN with the Starlink and I really don't want to turn off the DHCP on Starlink because I loose full control of the unit. It becomes a pain when I have to stow and unstow the unit because it lost the signal and isn't autotracking. This happens often as the unit is on a boat and I anchor a ton so we swing around constantly.

So I have a Double WAN issue and the unit is not handling well.

How do I get the unit to deal with the Double WAN through the primary WAN port and then load balance between the built in modem in the /dev/cdc-wdm0 device slot

Please note that while I am tech savvy, I am very new to the OpenWrt world, so a little bit of patience on your end would be greatly appreciated.

Thank you.

mwan3 package does what you need.