- Operates at the transport layer (TCP/UDP).
- Routes traffic based on IP address and port only.
- Doesn’t inspect the content of the request.
- Faster and more lightweight than Layer 7.
- Suitable for protocols like HTTP, HTTPS, FTP, SMTP, WebSockets.
- Commonly used for high-performance, low-latency systems.
- Tools: HAProxy, NGINX (stream module), AWS NLB.