The Citrix licensing system involves three components: the license server for managing licenses, licenses for each product that you purchase and the monitoring and metering functions built in each product.
Setting up the License Server
To set up your Citrix environment to manage licenses, you must first create at least one License Server to store and manage license file(s). Available for Windows and UNIX, the Citrix License Server is a lightweight component that can be installed on the same system as a Citrix product for smaller deployments, or on one or more dedicated systems for larger deployments. You should associate this License Server or group of servers for open network communication with the Citrix servers you are licensing and then configure the Citrix product(s) to use licenses from that License Server or servers.
After you purchase a Citrix product, request a product evaluation or upgrade to a higher edition, you should click on the activation link in the confirmation e-mail to get your license entitlement(s). You may also visit My Citrix, your personalized section of the Citrix web site. Learn more about getting Citrix product licenses.
Monitoring and Metering Licenses
Licenses can be checked out to a user, device, session, server or appliance, depending on the licensing model for each product. Learn more about licensing models by product.
All licenses are contained in a pool on the license server(s). License check-out is triggered based on product-specific system activity.
When an activity begins, the product requests a license from the License Server. If the appropriate license is available, the License Server checks it out and associates it accordingly.
In the event a product loses communication with the License Server, the product will continue to function for a predetermined license grace period. As an additional precaution, Citrix also recommends that customers back up licenses and the license server.