I need to block all communication (inbound/outbound) from server A to server B (all ports/all protocols). Server A should communicate with every machine except server B. I can't place firewall rules on server B, so I have placed all rules on server A.
I have done the following on server A:
- First I disabled all default firewall rules (inbound/outbound) on server A. (This is required.)
- Then I created an inbound rule that allow access from anywhere.
- Then I created an inbound rule that deny access to server B (all protocols/ports).
- Then I created an outbound rule that deny access to server B (all protocols/ports).
I have tested that the access is restricted via ping from both servers, and it seemed to work. But then I installed Nmap on server A and scanned server B. My assumption was that Nmap would not be able to scan server B, as the firewall would block it. But Nmap is able to scan open ports of server B. How is that possible?
Windows Server 2008 is installed on both machines.