CRS326 – How to enable hardware offloading with bonding (active-backup mode)?

RouterOS General
1

Hello,
I am working on a CRS326-24G-2S+RM and I have to configure a bonding interface in active-backup mode between two Ethernet ports, while keeping hardware offloading enabled (so traffic stays in the switch chip and does not hit the CPU).
While reading the MikroTik documentation, I found some inconsistencies: in some pages, it is stated that active-backup bonding can be handled directly by the switch chip, without involving the CPU, but in other sections, hardware offloading is mentioned only for balance-xor or LACP (802.3ad), and active-backup is not clearly referenced.
So I am trying to understand what is actually supported on CRS3xx devices (specifically CRS326).

Is hardware offloading fully supported for bonding mode=active-backup on CRS326?
If yes, what is the correct configuration approach to ensure that traffic remains in the switch chip?

Thank you in advance for the clarification.

2

[SOLVED]

Just an update in case this helps others.
The issue was related to the RouterOS version. After upgrading to RouterOS 7.21.3, hardware offloading started working correctly with bonding in active-backup mode on my CRS326-24G-2S+RM.
I tested with sustained high traffic load, and CPU usage now remains below 5%, which confirms that forwarding is handled by the switch chip and not by the CPU.
So if anyone experiences high CPU usage with active-backup bonding on CRS3xx devices, I strongly recommend upgrading to RouterOS 7.21.3 or newer.

Thanks.

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