What is TLS in a Load Balancer?
TLS (Transport Layer Security) is a cryptographic protocol used to secure communication over the internet. In the context of a load balancer, TLS is responsible for encrypting and decrypting traffic between clients and backend servers.
Why TLS in a Load Balancer?
A load balancer handles TLS termination, passthrough, or bridging to:
✔ Secure data transmission over the network.
✔ Improve performance by managing encryption workloads.
✔ Protect backend servers from direct exposure to threats.
✔ Enable traffic inspection for security policies.
Types of TLS Used in Ingress Load Balancer
1. SSL Passthrough
SSL Passthrough forwards encrypted HTTPS traffic directly to the backend servers without decrypting it at the load balancer.
🔴 Cons:
- The load balancer's capabilities are minimally used, potentially causing latency issues.
- Malicious traffic, including hacking attempts, can pass directly to the backend server without inspection.
2. SSL Offloading (SSL Termination)
SSL Offloading decrypts all HTTPS traffic at the load balancer before forwarding it as plain HTTP to the backend servers.
🟢 Pros:
- Reduces processing load on backend servers, improving performance and lowering latency.
🔴 Cons:
- Data is vulnerable to theft and man-in-the-middle attacks since it is transmitted unencrypted beyond the load balancer.
3. SSL Bridging
SSL Bridging decrypts HTTPS traffic at the load balancer, inspects it, and then re-encrypts it before sending it to the backend servers.
🟢 Pros:
- End-to-end encryption enhances security.
- The load balancer can inspect and validate traffic for potential malware or attacks.
🔴 Cons:
- Requires additional processing power, increasing computational overhead and cost.
