A network element is described. In one embodiment includes receiving a packet from the host in the first domain at the network element in the first domain, the packet including a destination address to the host in the second domain, the destination address being formed by replacing an Interface Identifier of an IP address by a second domain label and a shortened Media Access Control (MAC) address, the second domain label identifying the second domain. A routing label and the shortened MAC address are attached to the received packet, and the packet is sent on a label switched path indicated by the label to the second domain.