7. Orchestration and Extension : 7.2 Cloud Provisioning with vFabric Application Director : 7.2.3 Guest Customization and the vFabric Application Director Agent
   
7.2.3 Guest Customization and the vFabric Application Director Agent
Virtual machine templates consumed by vFabric Application Director must have the vFabric Application Director agent installed.
1. On first boot, virtual machines deployed by vFabric Application Director in the vCloud provider environment go through the vCloud guest customization process.
2. At the end of guest customization, the vFabric Application Director agent on each deployed virtual machine initiates contact with the vFabric Application Director server and downloads the latest version of the agent software.
3. The agent downloads the service scripts and creates environment variables that correspond to properties created in the service or blueprint.
4. Service scripts can then be executed to install, configure, and start software on each deployed virtual machine.
The vFabric Application Director agent in each virtual machine establishes the connection to the vFabric Application Director server. This reduces the complexity of firewall management.