The WPA271 occupies an IP address, under which you will find its browser interface.

Hmmm ... you'd be transporting two logical networks on the same physical media. With plain LAN cabling, that's entirely possible, and I've done it before; with PLCs I've never tried, though I don't...

WPAs are managed through their own browser interfaces.

Of course not. Your 4020Ps both are upstream of the router, and therefore not seen by its downstream services like DHCP.

The 8030P in themselves perform very well. With the typical three-phases wiring in German houses, you will always find that certain rooms won't receive good signal if the pair of PLCs is on different...

That's fine then - as for the firmware update, I have no further advice for you. The few times I've done this, with very old TL-PA251 and recent TL-PA8030P, it worked, no tricks involved. For all...