VMG4825-B10A - Mac running Mojave drops ethernet on Zyxel bonded DSL router: Where is the problem?

Mundeli

Hey All,
I'm fine for days at a time, then I find the ethernet connection has gone south.
I've got two adapters, Thunderwire and USB3, both exhibit same issues.
Have rebooted my machine, still doesn't connect.
So I use WiFi, then some time later it will connect.

Router is: a Zyxel VMG4825-B10A, bonded DSL (two DSL lines in one).

Before, when I had a single DSL line, and the simple Comtrend modem, there was never an issue (for years).  Since upgrading to latest router, I've had this issue. 

If I go to the admin page, I see that the NAS (which is short 3' patch cable away) is still happily connected.

How can I tell if this is an issue with my Mac, versus an issue with the router (versus wiring)?

Thanks for any suggestions


#SP_Jun_2019