appearently, this doesn't work:
PRTG on a w2k8 machine connecting to a w2k3 server via WMI and IPSEC (not normal windows firewall) set in a way, that all traffic between the monitor server and the w2k3 server is allowed.
but this does:
PRTG on a w2k8 machine /with an elastic IP assigned/ connecting to a w2k3 server via WMI and IPSEC (not normal windows firewall) set in a way, that all traffic between the monitor server (the elastic IP) and the w2k3 server is allowed.
we tried hard for a day until we realized, that amazon is somehow messing with the internal IPs (mabey another firewall) and that you need to speak to the AWS server via the elastic IP.