Global Sever Load Balancing (GSLB)

Global Server Load Balancing ensures that users are directed to the best available application instance across multiple geographic locations.

The diagram shows how DNS queries are handled by multiple FortiADC devices across regions to enable global server load balancing and direct users to the best data center.

When a client accesses an application (for example, www.example.com), FortiADC uses DNS-based logic to return the most appropriate server IP based on:

• Availability – Only healthy data centers are selected

• Proximity – Users are directed to the closest location to reduce latency

• Performance – Traffic is routed to the best-performing server

• Failover – If a local site is unavailable, traffic is redirected to a backup site

This approach enables organizations to:

• Deliver applications with low latency and optimal performance

• Ensure high availability and business continuity across regions

• Seamlessly handle traffic spikes and regional outages

• Provide a consistent user experience worldwide

For more information, see Global Load Balance in FortiADC Administration Guide.