The flight will update all VM agents in all subscriptions by the end of the deployment period. Also, if the VMs are in different regions, they might update on different days in the five-day period. Because of this, when a flight happens, you may see VMs in your host pool receive the agent update at different times. It takes 24 hours for all VMs in a single broker region to receive the agent update in a flight. These update periods are called "flights". New versions of the agent are deployed at regular intervals in five-day periods to all Azure subscriptions. For more information, see Scheduled Agent Updates. If you've already configured the Scheduled Agent Updates feature, the agent will only install the updated components during the maintenance window that you specify. If a newer version exists, the updated component is automatically installed by the flighting system, unless you've configured the Scheduled Agent Updates feature. After you've installed the initial version of the Azure Virtual Desktop agent, the agent will regularly query the Azure Virtual Desktop service to determine if there’s a newer version of the agent, stack, or monitoring agent available. You must always have the latest stable version of the agent installed so your VMs don't lose connectivity or security. Agent updates can include new functionality or fixes for previous issues. The Azure Virtual Desktop service updates the agent whenever an update becomes available. Unblocking these URLs is required to use the Azure Virtual Desktop service. To successfully install the Azure Virtual Desktop agent, side-by-side stack, and Geneva Monitoring agent, you must unblock all the URLs listed in the Required URL list.