SSL termination refers to the process of decrypting encrypted traffic before passing it along to a web server.
What is SSL termination?
Approximately 90% of web pages are now encrypted with the SSL (Secure Sockets Layer) protocol and its modern, more secure replacement TLS (Transport Layer Security). This is a positive development in terms of security because it prevents attackers from stealing or tampering with data exchanged between a web browser and a web or application server. But, decrypting all that encrypted traffic takes a lot of computational power—and the more encrypted pages your server needs to decrypt, the larger the burden.
SSL termination (or SSL offloading) is the process of decrypting this encrypted traffic. Instead of relying upon the web server to do this computationally intensive work, you can use SSL termination to reduce the load on your servers, speed up the process, and allow the web server to focus on its core responsibility of delivering web content.
How does SSL termination work?
SSL termination works by intercepting the encrypted traffic before it hits your servers, then decrypting and analyzing that traffic on an Application Delivery Controller (ADC) or dedicated SSL termination device instead of the app server. An ADC is much better equipped to handle the demanding task of decrypting multiple SSL connections, leaving the server free to work on application processing.
Why is SSL termination important?
Many security inspection devices have trouble scaling to handle the tidal wave of malicious traffic, much less decrypting, inspecting, and then re-encrypting it again. Using an ADC or dedicated SSL termination device to decrypt encrypted traffic ensures that your security devices can focus on the work they were built to do.
In addition, by using SSL termination, you can empower your web or app servers to manage many connections at one time, while simplifying complexity and eliminating performance degradation. SSL termination is particularly useful when used with clusters of SSL VPNs, because it greatly increases the number of connections a cluster can handle.
Offloading SSL or TLS traffic to an ADC or dedicated device enables you to boost the performance of your web applications while ensuring that encrypted traffic remains secure.
How does F5 handle SSL termination?
BIG-IP Local Traffic Manager (available in hardware or software) offers efficient and easy-to-implement SSL termination/offload that relieves web servers of the processing burden of decrypting and re-encrypting traffic while improving application performance.
Alternatively, SSL Orchestrator delivers dynamic service chaining and policy-based traffic steering, applying context-based intelligence to encrypted traffic handling to allow you to intelligently manage the flow of encrypted traffic across your entire security chain, ensuring optimal availability.