Various exemplary embodiments are a method and of discovering medium access control (MAC) addresses in a network and a related access node including one or more of the following: receiving, at an access node, a diagnostic message from an operator, the diagnostic message comprising physical port information and indicating that at least a portion of a MAC address of a destination bridge port is unknown to the operator; forwarding the diagnostic message to a respective bridge port of the access node; determining whether the physical port information specified in the diagnostic message corresponds to a physical port of the respective bridge port; and sending a reply message to the operator specifying a MAC address of the respective bridge port.