My internet box has a router integrated (probably like most boxes), but I can
put it in bridge mode and use the modem only (and use a libre router).
So, since the modem and the BCL can't be avoided (but the router can be), at
least they don't imply using non-free software on our PCs.
But then at the minimum, as you say, encryption is mandatory.
To illustrate what such a software does, here's one called Cockpit from
Devolo:
In addition to numerous status displays, such as the connection quality of
the individual dLAN® adapters, the intuitively operated program also offers
control over encryption and configuration. With targeted tips and other
useful features, a software wizard provides for optimisation of the
transmission rate in the dLAN® network and enables adapter updates over the
network.
Some more:
Configure the devolo devices as usual:
Start dLAN® Cockpit.
Enter the security IDs of all dLAN® adapters.
Assign the shared network password.
Now, assign the other HomePlug devices the same password as the dLAN®
devices according to the manufacturer‘s instructions.
I got more info from Youtube (https://www.youtube.com/watch?v=faL8evtPBJs).
Changing the default password (since there's a slim chance of the emitted
waves to allow access from outside, if I understood that right) and getting
updates would be nice though.
But I suppose it's overkill.
