Ipsec aware load balancer with minimal decryption

Abstract

While organizations can employ IPsec based VPNs to securely connect different sites (e.g., branch sites, data centers, and/or virtual private clouds), the security can disrupt network performance by obfuscating information used for load balancing. Disclosed is technology that employs minimal decryption in a secure manner to load balance multiple network traffic flows within a secure connection ('tunnel') across security appliances that effectively operate as alternative endpoints for the tunnel. The security appliances within a load balancing pool are configured/programmed to share tunnel keys with each other after tunnel establishment and with the load balancer. The load balancer uses the tunnel keys to minimally decrypt in a lookaside memory encrypted packets to ascertain N-tuples. The load balancer then uses the N-tuples to load balance the flows within a tunnel across the security appliances.