On the network shown in Figure 1, the NPE functions as an exterior gateway. When hosts attached to the CE need to access the Layer 3 network, the MAC address of the gateway is required. If the MAC address does not exist, the hosts send Address Resolution Protocol (ARP) requests to the NPE over VPWS. The NPE terminates VPWS, analyzes the ARP requests, and generates related ARP entries. Later, when receiving a packet, the NPE checks the MAC address carried in the packet. If the MAC address carried in the packet is the MAC address of the NPE, the NPE forwards the packet to the L3VPN.