Lowest system priority (a 2-byte priority value followed by a 6-byte switch MAC address) is allowed to make decisions about what ports actively are participating in the EtherChannel at a given time.
Ports are selected and become active according to their port priority value (a 2-byte priority followed by a 2-byte port number), where a low value indicates a higher priority. A set of up to 16 potential links can be defined for each EtherChannel. Through LACP, a switch selects up to eight of these having the lowest port priorities as active EtherChannel links at any given time. The other links are placed in a standby state and will be enabled in the EtherChannel if one of the active links goes down.