@bonestaak If you use the Omada controller I believe that should do it.

@luft It's hard to predict whether the switch would work properly. Of course there would be a voltage dropout due to the cable length and it may or may not work - the only way to check that is to...

@HarveP Your modem router is an ISP provided device and it's not supported by the community as @David-TP already pointed. Hence your only option is to chase your ISP about the VoIP configuration...

@bonestaak Your Pi hole DNS IP address can be set here:

@Leray22222 Your question can be answered only by a TP-Link representative. This option is matter of a FW implementation and I'm not sure that even they have that answer.

@Tmaz Contact your local support and let them advise you on this issue.