SEP 12.1 don't disable Windows Firewall entirely
I stumbled upon this error the other week at a customer. They had problems running GPRESULT on remote machines with SEP 12.1. All their machines have NTP enabled so it was easy for them to first blame that. To my knowledge NTP doesn't deny that kind of traffic. I tried to disable NTP without result. When clicking around a bit I found that Windows Firewall seemed to be enabled although we'd disabled it through SEP policy.
According to this article this is an expected behavior and shouldn't do any harm.
Advanced Settings for Windows 7 Firewall indicate that it is on, even when Symantec Endpoint Protection (SEP) Network Threat Protection (NTP) is installed http://www.symantec.com/docs/TECH123729
According to me this is exactly what's creating my problem!
When I disable Windows Firewall through the Advanced Firewall Settings I suddenly can do all sorts of GPRESULT on remote machines. Please note that we have made the settings in SEP Firewall Policy to Always Disable Windows Firewall.
This is what the "standard" Firewall Status originally shows
This is what the Windows Firewall with Advanced Security shows
Now I click on Windows Firewall Properties to really turn off Windows Firewall (this is easier done on larger scale through GPO)
This is how you'd want the Windows Firewall with Advanced Security to look like