LACP hold-up timer configuration support on LAG interfaces

You can configure a Link Aggregation Control Protocol (LACP) hold-up timer value for link aggregation group (LAG) interfaces. You configure the hold-up timer to prevent excessive flapping of a child (member) link of a LAG interface due to transport layer issues. With transport layer issues, it is possible for a link to be physically up and still cause an LACP state-machine flap. An LACP state-machine flapping can adversely affect traffic on the LAG interface. To prevent this, a hold-up timer value is configured. LACP monitors the PDUs received on the child link for the configured time value, but does not allow the member link to transition from the expired or defaulted state to current state. This configuration thus prevents excessive flapping of the member link. To configure the LACP hold-up timer for LAG interfaces, use the hold-time up timer-value statement at the [edit interfaces ae aeX aggregated-ether-options lacp] hierarchy level.