Classic Load Balancer provides basic load balancing across multiple Amazon EC2 instances and operates at both the request level and connection level. Classic Load Balancer is intended for applications that are built within the EC2-Classic network. We recommend Application Load Balancer for Layer 7 traffic and Network Load Balancer for Layer 4 traffic when using Virtual Private Cloud (VPC).
You can load balance HTTP/HTTPS applications and use Layer 7-specific features, such as X-Forwarded and sticky sessions. You can also use strict Layer 4 load balancing for applications that rely purely on the TCP protocol.
Classic Load Balancer supports SSL termination, including offloading SSL decryption from application instances, centralized management of SSL certificates, and encryption to back-end instances with optional public key authentication. Flexible cipher support allows you to control the ciphers and protocols the load balancer presents to clients.
Classic Load Balancer supports the use of both the Internet Protocol version 4 and 6 (IPv4 and IPv6) for EC2-Classic networks.