An apparatus including a service network and a plurality of Layer 2 sites connected by the service network via a plurality of gateways is provided. The gateways are configured to map a plurality of Internet Protocol (IP) addresses of a plurality of hosts under a plurality of virtual local area networks (VLANs) in a plurality of Layer 2 sites to a plurality of addresses (e.g., MAC or others) of the corresponding other gateways, inform the other gateways in other Layer 2 sites of the IP addresses mapped under each of the VLANs in the local Layer 2 sites, and forward data frames originated from the hosts in the local Layer 2 sites to the other gateways in the other Layer 2 sites when destinations of the data frames are residing in the other Layer 2 sites.