My CSS318-16G-2S+ switch running SwOS 2.17 blocks DHCP when any kind of LAG is active.
This is irrespective of any combination of “Trusted Ports” and “Add Information Option” ticking/unticking in the "System" menu.
Simply, when any LAG (passive, active, static LAG / LACP) is active, the switch blocks all DHCP. This even occurs when the switch is placed in the middle of other 3rd party switches, it then blocks DHCP passing across the chain.
This is easily reproducible by configuring a 2-port LAG, then observing DHCP is blocked. Then disable one of the ports in the “Link” settings (leaving all LAG config in place, effectively simulating a port fail scenario) and DHCP is now working correctly. You can then re-enable the port and observe that DHCP is once again blocked.
Has anyone else encountered something similar either on CSS318 or SwOS 2.17 etc ?
EDIT: This is when using LAG as a VLAN trunk.
EDIT2: viewtopic.php?t=205504
Known bug with other models, still present in 2.17 on my CSS318
EDIT3: Case raised with Mikrotik:
Hello,
Thank you for the report!
We have managed to reproduce the issue locally in our labs and look forward to fixing it on upcoming SwOS versions, unfortunately, I cannot provide a release date now.
Best regards,