Network Access Control

We are having this random problem where on some machines the Internet and mail connection goes down but the connection to network drives, Remote desktop, ping etc remains active.  If I unload SEP, first disabling SEP in the system tray then running smc -stop the connection returns.  WE are running the latest?? SEP 11.0.6000.5500 and the affected machines are all up to date.  For browsing we use firefox 3.63 and outlook 2007 but I think the problem persists in IE 8.  Any light on this would be appreciated

Check the NTP logs and find which rule is blocking the packets..

Can you give us an update us on your Issue?

Thanks,
Thomas

Sorry, didnt see that there were any responses.  I will check and get back asap

The log for NTP are empty

What features of SEP are installed on these systems? Is this happening with wired, wireless or both?

Check out this KB -

Symantec Endpoint Protection appears to cause networking problems with NICs using a TCP Offload Engine

http://service1.symantec.com/support/ent-security.nsf/854fa02b4f5013678825731a007d06af/f8d5bf6d26acc395882574a60071701b?OpenDocument

Features
Antivirus and antispyware protection
proactive Threat Protection
Network Threat protection

and these are all wired connections and I think we are all uptodate 

Is it possible to run Wireshark and collect a packet capture when your internet connection is lost? Be sure to browse your network drives durring this capture.

Look into at soon as I can.  People are on holidays so Im pulling double duty.  Thanks for the suggestion.