Virtual leased line address resolution protocol cache for customer edge internet protocol addresses

A provider edge node for allowing a customer edge device to access a Virtual Leased Line (VLL) service, the provider edge node comprising:

• a cache that is configured to store an association between an Internet Protocol (IP) address of the customer edge device and a Media Access Control (MAC) address of the customer edge device;
• a backup memory that maintains a persistent copy of a last-known IP address of the customer edge device during a cache-clearing event in the cache, wherein the backup memory does not store the MAC address;
• a communication interface that is configured to transmit data packets to the MAC address of the customer edge device;
• and
• a processor that is configured to update the cache upon receipt of an address update message from the customer edge device, the address update message indicating the IP address and the MAC address of the customer edge device, removes the stored association from the cache in response to the cache-clearing event, while maintaining the persistent copy of the last-known IP address in the backup memory, wherein the cache-clearing event temporarily interrupts connectivity to the customer edge device, at a time subsequent to removal of the stored association from the cache, sends an address discovery message using the communication interface, the address discovery message requesting an updated MAC address corresponding to the last-known IP address maintained in the backup memory, and updates the cache to reflect the updated MAC address upon receipt of an additional address update message from the customer edge device, wherein the address update message and the additional address update message are Neighbor Discovery Protocol advertisements and the address discovery message is a Neighbor Discovery Protocol solicitation.