On Fri, Jul 25, 2025 at 11:49:00AM +0300, Nikolay Aleksandrov wrote:
On 7/25/25 09:28, Hangbin Liu wrote:
When `lacp_active` is set to `off`, the bond operates in passive mode, meaning it only "speaks when spoken to." However, the current kernel implementation only sends an LACPDU in response when the partner's state changes.
As a result, once LACP negotiation succeeds, the actor stops sending LACPDUs until the partner times out and sends an "expired" LACPDU. This causes continuous LACP state flapping.
According to IEEE 802.1AX-2014, 6.4.13 Periodic Transmission machine. The values of Partner_Oper_Port_State.LACP_Activity and Actor_Oper_Port_State.LACP_Activity determine whether periodic transmissions take place. If either or both parameters are set to Active LACP, then periodic transmissions occur; if both are set to Passive LACP, then periodic transmissions do not occur.
To comply with this, we remove the `!bond->params.lacp_active` check in `ad_periodic_machine()`. Instead, we initialize the actor's port's `LACP_STATE_LACP_ACTIVITY` state based on `lacp_active` setting.
Additionally, we avoid setting the partner's state to `LACP_STATE_LACP_ACTIVITY` in the EXPIRED state, since we should not assume the partner is active by default.
This ensures that in passive mode, the bond starts sending periodic LACPDUs after receiving one from the partner, and avoids flapping due to inactivity.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Shouldn't the fixes tag be lacp_active commit id? E.g. 3a755cd8b7c6 ("bonding: add new option lacp_active")
Totally forgot that I added this option -_-!!
Thanks Hangbin