Acronis Backup & Recovery 11.5 Management Server uses TCP ports 443,902, and 9876 for operations with Agent for ESX(i) (Virtual Appliance). Make sure that the management server can access the vCenter Server and the ESX(i) hosts through these ports:
If the management server uses a custom firewall, make sure that this firewall does not block outgoing connections through these ports. Windows Firewall is configured automatically by Acronis Backup & Recovery 11.5.
If the traffic from the management server goes through a router or a similar network device, make sure that the device does not block this traffic.
No special configuration is required on the vCenter Server or the ESX(i) hosts themselves.