This is the destination UDP port the switch sends 802.1X accounting messages to on this server; per the object's own description, a value of 0 disables use of this server, and the source description reuses the wording not used for authentication, reflecting that this object was likely copied from the authentication table's port object. Setting this to 0 lets an admin pull an accounting server out of service without deleting its row, useful when decommissioning or maintaining an accounting collector while keeping its configuration for later reuse. For example, the standard RADIUS accounting port 1813 would normally be configured here, and an admin performing planned maintenance on the accounting server might temporarily set this to 0.