Get DtD services working

Basically, that's exactly how it is supposed to work. You'll only advertise the service from one node. Each node will have it's LAN segment with a separate IP range. In this case, it sounds like it ison the 5G node's address space, so that's the node that would advertise it. Anything connected out from the 2.4ghz node, be it local on that node's address space, or via another node, will route through the 2.4 GHz node, out vlan2 for DtD linking to the 5 GHz node, and out to the service advertised. The return traffic will take a similar trip. In order to advertise the service from both nodes, you'll need to have your service have multiple IP addresses, one on each of the nodes' LAN segments.

Some dumb switches will pass VLAN tagged traffic without messing it up, and some won't.  The dumb switch that I have here at home for my DtD traffic does just fine with the VLAN 2 for DtD.  If I were to plug a device other than a node into the switch, I would get an address off the Rocket M3 that plugs into the switch because it is the only node that has the LAN on the same physical port as the DtD (the other two are Mikrotik hAP based nodes).