1. A method for generating, by a transport network device of a second type, information about a newly added port belonging to a linked device of a first type and associated with a transparent LAN segment, the information to be disseminated to other devices of the second type, the method comprising: a) obtaining, by the transport network device, a set of labels associated with the newly added port; and b) generating, by the transport network device, at least one message, the at least one message collectively including i) a first field for identifying the device of the second type; ii) a second field for identifying the transparent LAN segment to which the newly added port belongs, iii) a third field for identifying the device of the first type in the context of the transparent LAN segment, and iv) a fourth field for identifying the set of labels.