What is Azure Load Balancer?

An Azure Load Balancer distributes inbound network traffic across multiple backend resources (VMs or VM Scale Set instances) to ensure high availability and reliability. It operates at Layer 4 (TCP/UDP) and provides sub-millisecond latency. Types: Public Load Balancer: distributes internet traffic to VMs. Internal (Private) Load Balancer: distributes traffic within a VNet. Key features: Health probes: detect unhealthy instances and remove them from rotation. Load balancing rules: define how traffic is distributed (5-tuple hash by default). Inbound NAT rules: map specific ports on the public IP to specific VMs. For HTTP/HTTPS load balancing with URL-based routing, SSL termination, and WAF, use Azure Application Gateway instead.