Slow VLAN speed in one direction between two Mikrotik routers

RouterOS Beginner Basics
1

Hello all, I used to have hAP AC doing all the routing stuff that I needed, but now that I want to expand the network over my home, I have stumbled upon a weird problem, which I have noticed by testing wifi speed from over my phone, but for testing purposes I’ll be explaining it with two routers and file transfer over two windows PCs.

I use hEX Poe as a core router and a DHCP server, and hAP ac as an AP. I have made a bridge of 3 VLANs (menagement, private, guests), and bridged the bridge to ethernet2 port on hEX Poe, and made a bridge of VLAN bridge on the hAP AC as well, and everything is working well as I imagined it.. but!! When I transfer file over windows share ( PC1 → hAP AC → hEX POE → PC2), the speed of the transfer is locked at 11 MB/s (95Mbps showing on Mikrotik interface) without showing serious CPU usage on both routers (under 30%).. and when I transfer file in opposite direction (PC2 → hEX POE → hAP AC → PC1), the speed is reaching up to 80MB/s and transfering a file in an instant. When I remove the VLAN Bridges and use a single direct bridge between those two routers, that problem dissapear and the speed gets to 80MB/s with no problems in both transfer direction.
I used to have 230Mbps upload and 250Mbps download from my phone to an FTP server on PC over hAP AC itself, and now when it’s hAP AC and hEX Poe together it’s 90Mbps upload and 270Mbps download.
Both routers have 6.42.1 version packages with RouterBoard updated to 6.42.1

tl;dr - Using only hAP AC or only hEX Poe shows great transfer speed results, or when those two routers are bridged directly.. but when they are bridged over VLANs there’s a weird transfer speed drop to 95Mbps in one direction

Things I have tried:

  • Changing the cable between Mikrotiks (I’m using Cat.5e cables)
  • Using direct PSU for both routers (no POE)
  • Using different devices with gigabit ethernet and/or 5GHz wifi (Laptop, Phone) for speed testing
  • UDP Bandwidth test between the Mikrotik devices in VLAN show about 400Mbps speed in each direction without any problem.
  • btest.exe test between the two computers with same result and problems
  • Tried downgrading to 6.40.8

Things I may do soon:

  • Try to reset both routers and try setting them up again by doing a minimal functional configuration of VLANs

Thanks for reading me out, I hope we can manage to find a solution

2

I solved it by resetting the hEX Poe and setting it up again.. I’ll try to check what went wrong

3

So.. apparently it isn’t smart to bridge two ports with having VLAN’s on the bridge instead of the interfaces if you have one port with 1Gbps router (hAP AC) and the other with 100Mbps (hAP AC Lite)

4

good to know. VLAN settings are getting a bit consuming to me now.

5

Yeah, so instead of doing something like this on a bridge between two ports:
xEM65zw.jpg
You should try this since it might fix the problem:
Xb3gh7p.jpg