Configuring LACP

A dynamic LAG is LACP-enabled, and LACP is run on every candidate port defined in the LAG.

LACP Priority and Rules

LACP system priority and LACP port priority are both used to determine which of the candidate ports become active member ports in a dynamic LAG configured with more than eight candidate ports.

The selected candidate ports of the LAG are all connected to the same remote device. Both the local and remote switches have a LACP system priority.

The following algorithm is used to determine whether LACP port priorities are taken from the local or remote device: the local LACP System Priority is compared to the remote LACP System Priority. The device with the lowest priority controls candidate port selection to the LAG. If both priorities are the same, the local and remote MAC addresses are compared. The priority of the device with the lowest MAC address controls candidate port selection to the LAG.

A dynamic LAG can have up to 16 Ethernet ports of the same type. Up to eight ports can be active, and up to eight ports can be in standby mode. When there are more than eight ports in the dynamic LAG, the switch on the controlling end of the link uses port priorities to determine which ports are bundled into the LAG and which ports are put in hot-standby mode. Port priorities on the other switch (the non-controlling end of the link) are ignored.

The following are additional rules used to select the active or standby ports in a dynamic LACP: