Introduction

FortiOS server load balancing includes the features you would expect of any server load balancing solution. Traffic can be distributed across multiple backend servers based on multiple methods including static (failover), round robin, weighted to account for different sized servers, or based on the health and performance of the server including round trip time, number of connections. The load balancer supports HTTP, HTTPS, IMAPS, POP3S, SMTPS, SSL or generic TCP/UDP or IP protocols. Session persistence is supported based on the SSL session ID or based on an injected HTTP cookie.

Before you begin

Before you can configure server load balancing on the GUI go to System > Feature Visibility and turn on Load Balance. Its in the Additional Features list.

To be able to use all of the features described in this chapter you should go to System > Settings and setting the Inspection Mode to Proxy. If Inspection mode is set to Flow-based, you can only configure Virtual Servers with Type set to HTTP, TCP, UDP, or IP. Proxy mode is required for persistence, HTTP Multiplexing, SSL offloading and other advanced HTTP and SSL features.