Q: We disabled the Windows Firewall: Allow ICMP exceptions setting via Group Policy to prevent certain systems from responding to ping requests. However, those systems are still responsive. We’ve verified that the policy is being enforced, but something seems to be overriding it. Can you explain what's happening?
A: Apparently, you've created a Windows Firewall exception for TCP port 445, which Windows uses for file and printer sharing. If you enable any kind of exception that opens TCP port 445, Windows Firewall begins allowing inbound echo requests in answer to pings. When you create a port exception for 445, you must enable both Windows Firewall: Allow file and printer sharing exception and Windows Firewall: Allow remote administration exception to stop incoming ping requests. I don’t know why these exceptions stop pings; it’s just a weirdness of Windows.