Bridge VLAN does not work completely until re enabled

RouterOS General
1

Hi there

On some of my CRS309 (RouterOS v7.1.1) I’m facing the issue that sometimes a VLAN is not working on all ports in a bridge vlan setup.
Disabling and re enabling the vlan under /interface/bridge/vlan helps.

Is there maybe a bug?

Best regards
Patrick

2

I did some more troubleshooting. It looks like VLANs are working. But if a bridge host moves from one MLAG to another (e.g. if I move a VM between 2 MLAG-connected servers), the MLAG slave switch does not update its bridge host table. Even after some hours of waiting, it still shows the old bonding under /interface/bridge/hosts.

After disabling/enabling the affected VLANs on the slave switch, the MAC address is learned again on the correct MLAG port.

Sounds like a bug

3

I have faced, probably the same problem multiple times with RouterOS 7.1 and 7.1.3. I did not test the versions in between.
If a MAC address is moved from one MLAG bond to another MLAG bond without disconnecting the cables from the ports that are associated with MLAG bond where the MAC address was reachable first, one of the switches never updates it’s host entry for the moved MAC address.
I’m not sure if the problem is VLAN dependent but I observed the problem always on MLAGs that transports ethernet frames with VLAN tags.

I have now created a bug report for the problem (SUP-77486) at MikroTiks servicedesk.

4

Same problem.
Is it fixed in new stable (7.1.4 - 2022.03.21) release?

5

Hi @mazza

Thanks for your reply!
In the meantime, MikroTik was able to reproduce it & is working on a fix:

Hello,

Thank you for the report!

The MLAG does not correctly update the FDB table on the opposite peer when the MAC address is moved to a different port.

We have managed to reproduce the issue locally in our labs and look forward to fixing it on upcoming RouterOS versions, unfortunately, I cannot provide a release date now.

Best regards,

Best regards
Patrick

6

Hi @fbauer,

I don’t think the moving MAC on MLAG Problem is fixed in Router OS 7.1.4 (2022-03-21) since MikroTik told me on the same day (2022-03-21) that they was able to reproduce the problem, and that they will fix it in an upcoming RouterOS versions. However, they can not provide a release date yet.


Hi @patrick7,

thank you for sharing you discussion with MikroTik.


best regards,
Sebastian

7

Hi Sebastian,

did you test this bug with new release? (v7.2 Stable)
Is it fixed?

Regards,
Ferenc

8

Good news, MikroTik provided me with a development version, where this bug is fixed.
They expect the fix to be released soon.

9

The fix is released!
http://forum.mikrotik.com/t/v7-3rc-testing-is-released/157306/1