VLANs via power line

RouterOS Beginner Basics
1

Hi,

I want to share three VLANs due power line adapters.
Must the power line adapters support 802.1Q or 802.1p VLAN tagging feature or can I just connect a power line adapter to a tagged port on which 3 VLANs are assigned?

Moreover, the alternative solution, I am looking for, is a power line adapter which offers a internal WiFi interface for VLAN 10 and VLAN 20 and maybewith a LAN port which offers untagged VLAN 30.

I only found old devices with 802.1Q feature:

  • TP-Link TL-PA9020P Kit
  • Devolo dLAN 1200+
  • Netgear Powerline 1200 Mbps Adapter (PLP1200)

The two power line adapters from Mikrotik are also discontinued products.

When I use a managed switch on the second power line adapter, the VLANs should be transfered due power line adapters, shouldn’t?

Thanks, very much.

2

Do they really support VLANs?

3

I have found a report that Devolo models 8254 and 8504 (of the newer 2400 Magic 2 series) do let VLAN’s pass through:
https://forums.overclockers.co.uk/threads/psa-devolo-magic-2-next-does-not-pass-tagged-vlan-traffic.18908918/
but it has to be checked, maybe it is not a “by design” feature and it happens to work only on some revision(s), in any case at best two such devices can only “transport” the packets unmodified.

4

A lot of non-VLAN aware devices will successfully pass VLAN traffic just fine - however some will not. You really have to test non-VLAN aware devices to make sure.
I am using a non-VLAN aware dumb switch for some VLAN traffic and it works just fine.

As for power line network adapters - don’t get your hopes up too much. Reliability and throughput is generally poor. Not recommended unless you REALLY have no other choice.

5

Yeah the devolo ones look nice, They are acting much like wireless wire, in that its simulating an ethernet cable so you need smart devices on either side of the adapter to handle the vlan tags.
Should work.

6

The Comtrend PG-9182 PoE have explicit VLAN support:
https://us.comtrend.com/pg-9182poe/
https://us.comtrend.com/wp-content/uploads/2020/04/PG-9182PoE_UM_A1.0.pdf

7

When it comes to “non-VLAN” switches (power-line devices are switches with one “weird” ethernet port) … they will all happily pass VLAN tags (they are plain L2 devices and don’t look into “ethertype” header, even less they look any further into payload) … but they have to support slightly larger frames (that’s L2MTU in MT world). E.g. 802.1Q header (a.k.a. VLAN tag) adds 4 bytes to frame size … which with 1500 bytes IP MTU means 1504 bytes of L2MTU. Many “non-VLAN” switches support it, but not all.