Network Loop Killing my Network and Taking Away Users

Hey all,

I have a RouterOS 6.37.1 RouterBoard 2011UAiS with this setup:

I have a network loop that has been going on for 5 days now and I’m starting to lose my hair, and more importantly, my clients because of it.

Router Setup:
There are 2 bridges: In and Out.
The In Bridge: is responsible for connecting LAN devices to the Internet. It’s connected to UBNT PowerBean M5 400.
The Out Bridge: is responsible for connecting my LAN devices together. Every UBNT Nanostation is connection [wired/wireless] to the Out Bridge.

I have a PPPoE connection to my service provider.

What I tried:
I turned STP on all UBNT devices, except the two PowerBeam M5 400 (the Sender from my ISP, whom I can contact if needed, and the receiver above my house which I can access of needed)

I set priority in the In bridge to 0 (it was 8000) thinking this might help. It didn’t.

I turned priority in the root port of In bridge (called In2) to 0 thinking this might help.

I turned path cost of In2 to 20.

I turned on Auto Isolate in In Bridge, Out Bridge, In2 Port… Nothing helped.

I went to Bridge:Filters tab and added a rule there:
Chain: forward
In Bridge: In
Src MAC Address: 6C:3B:6B:0B::
Dist. MAC Address: 6C:3B:6B:0B::
Action: DROP and LOG

(I didn’t understand how to set STP tab here ^ so I left it alone)

I tried ALL variation of blocking some devices on my network by blocking them in DHCP and IP Binding from Hostspot

Notably, when I turn off DHCP and kick everybody out of the network and invalidate all DHCP Leases, the network (I think) comes back to normal.

The error itself is:
in2: bridge port received packet with own address as source address (6c:3b:6b:0b::), probably loop

I also tried replugging the PowerBeam dish into In1, which has a different MAC… However I started seeing In1 loops!



Help is greatly appreciated.