The image below illustrates how I am currently using a 2860Vac and a AP-710 at home. I originally wanted to use the AP-710 in "universal repeater" mode, but the building makes the two devices' radios invisible to each other, so I had to use the power line to connect them. The AP-710, then, is configured in "AP" mode, completely independend of the 2860, and without using the "central management" features.

This works, however it is unconvenient. The AP-710 must be configured independently, has its own wifi access points - with different names than the ones on the 2860 etc. If I wanted to be more strict with security - e.g. using bind IP to MAC - I need to configure all of it twice. There must be a better way.

The AP-710 user guide has a lot of information but also feels like it is taking a lot for granted, I probably don't know networking enough to understand it. What's your advice? Thank you in advance.

I think (and I'm in a similar position to you), that you need to use the 2860 as a WLAN controller and then pick up another AP710 (or newer) and place that near to the 2860 and use that to replace the wifi from the 2860 which is lost when you turn the 2860 in the WLAN controller. Both APs would then be corrected to the 2860 - one directly, and one via your ethernet-over-mains kit.

Yes, it does seem rather wasteful that that the 2860 can't be used to control its own Wifi and manage other devices (although I can sort of see the logic that in a more business environment you probably don't want wifi in your coms room)

On the face of it, after a bit of research and contacting support, they say:

"The wifi on the 2925 or any draytek router will work regardless of how many APs you connect to it,
What is not supported is roaming. So you can only connect to the wifi on the router if you are within the vicinity of where the router is located. "

https://www.draytek.co.uk/support/downloads/vigor-2925/send/269-vigor-2925/966-v2925-ug-v43
page 529 says:
Apply to Local
WLAN Profile configured in this page is specified for VigorAP connected to Vigor router. If required, these settings also can be applied to Vigor router. Select and check one of wireless profiles and click this button to apply the settings onto the Wi-Fi wireless settings configured for such Vigor router.


So that implies you can configure one profile and have both your 2860 and your AP-710 running it, however it seems that you can't roam between the wifi of the router and that of the APs it is managing, but you can roam between other APs it may be managing.