The ERPoe-5 is a router with three switched ports. The manual states that the switch ports are VLAN aware. I checked this before I bought it.
The switch that the ERPoe-5 is connected to is a dumb switch (Well, it atleast acts as one since I can't configure the PacketFront ONT), so that doesn't help me at all (and the switch at the other end of the ethernet cable is the receiving end. I can do _nothing_ on that end to fix the lack of vlans on the ERPoe). And routing is clearly not what I asked about in the first place. Routing won't pass DHCP, and I don't fancy the idea of routing 2,5gbps through the ERPoe-5 either.
I was recommended Ubiquiti equipment, but I see that actually trusting the product to deliver what it promises was a bit too much to ask. First and last attempt at buying Ubiquiti crap.