Probably Loop (bridge port receive packets with own address as source address

RouterOS General
1

Hello ,

I have causes error in Mikrotik router OS about the Probably loop in bridge port, I have attached the snapshot, Is there any solution of this error I have on RSTP in bridge interface.
My question to the Mikrotik expert
What actually causes the error is?

Thank you

Shanglakpam Prasanta Sharma
Mikrotik_LOOP Snap.png

2

Note that this message means that a packet, that was sent out from this device, was received back.
This means that something in your network is creating a loop and by logic this is most probably another device that is connected to that interface.

Make sure you have not used this type of configuration (or one of mentioned here):
https://wiki.mikrotik.com/wiki/Manual:Layer2_misconfiguration#VLAN_in_bridge_with_a_physical_interface

Note that in case you are using VLANs in your network, RSTP might not be sufficient in all cases and you should consider using MSTP instead.

3

What version RouterOS are you using? This cropped up a while ago and was a software warning (RB3011’s used to be a nightmare for it). Recent software is patched.

4

I’d never seen this message until after upgrading to 6.41.3

I didn’t think much of it because it seemed related to a client disconnecting & choosing a different nearby AP.

(1) second before the “own address as source” message being logged i see a client ~“disconnected, registered to other device in network”

I figured it’s something that’s either been going on and was never logged until after the upgrade - or maybe the clients (entirely Win10) got a new funky patch or something.

In this setup I have (2) RB2011’s & (2) hAP AC lite’s - & this message was only occurring on my RB2011’s

  • The hAP’s & 2011’s are nearly identical in overall operation & config - wlan1 & eth1 on a bridge (services handled on the back end) - clients choose whichever, nothing complicated & no VLANs

This morning i decided to take a second look, and noted my RB2011’s had “none” for STP whereas my hAP’s had RSTP on. This config inconsistency between the hAP & 2011’s is my fault, I’d t-shot some issues a year+ ago and I believe I forgot to flip them back. I’ve since turned RSTP on w/2011’s

I’ll keep an eye on it but i’m a little interested why i’d never seen this message logged before (in well over a year+) - 6.41.3 was the only “change” in our network. We haven’t added any new wireless clients for at least 6 months too.