editor RFC 3032 established two data link layer codepoints for MPLS: one to indicate that the data link layer frame is carrying an MPLS unicast packet, and the other to indicate that the data link layer frame is carrying an MPLS multicast packet. This specification updates RFC3032 by redefining the meaning of these two codepoints. The former "multicast codepoint" is now to be used only on multiaccess media, and it is to mean "the top label of the following label stack is an upstream-assigned label". The former "unicast codepoint" is to be used in all other cases. Whether the data link layer payload is a unicast MPLS packet or a multicast MPLS packet is now to be determined by looking up the top label, rather than by the codepoint. RFC3032 does not specify the destination address to be placed in the "MAC DA" field of an ethernet frame which carries an MPLS multicast packet. This document provides that specification. This document updates RFC 3032 and RFC 4023.