I have to put the PRTG monitor server behind a firewall. Now I can only monitor ICMP/PING. Which ports should be allowed in the Firewall to be able to scan Hyper-V and VMware VMs behind the firewall? I would like to read WMI counters, SNMP traffic, SQL2005 processes and running processes in the VMs. But also I need to be able to authenticate at Windows OS level and SQL level within the VM in order to read all system counters.