This read-write MacAddress is the configurable destination MAC address substituted into STP, CDP, or VTP frames whose disposition is set to pass-thru-l2pt: on encapsulation this address replaces the frame's destination address, and on decapsulation frames matching this configured address and the correct protocol signature are restored to their protocol-specific inferred MAC address. An administrator sets this to a value both ends of an L2PT tunnel agree on so tunneled control frames are not mistaken for locally destined traffic along the path. For example, configuring a distinct tunnel MAC lets a customer's CDP frames traverse the provider core disguised under that address until they are decapsulated and restored to the standard CDP MAC at the far end.