LACP

What is "Churn"
    state machines are unable to resolve the state of a given link, e.g., because the Partner System repeatedly sends conflicting information in its LACPDUs.

IN SYNC
    the link has been allocated to the correct LAG, the group has been associated with a compatible Aggregator, and the identity of the LAG is consistent with the system ID and operation Key information transmitted.

OUT SYNC
    the link is not in the right Aggregation