When Endpoint Protection 12.1 Firewall component is installed, computers briefly lose network connectivity after every boot
Last Updated May 14, 2018
When the Symantec Endpoint Protection 12.1 (SEP) firewall component is installed, computers briefly lose their network connection after every boot. When this issue occurs, the computer's network connection will begin working correctly again after a few seconds and this issue will not occur again until the next boot.
If the computer is booting from the network (as opposed to booting from disk), it is possible that this issue may prevent the operating system from loading properly.
SEP's firewall driver (teefer) does not have a boot flag associated with it. This causes Windows to start the firewall driver after the operating system has already started to load. When the firewall driver is loaded, a brief network interruption will be introduced.
To work around this issue, it is possible to create a boot flag for SEP's firewall driver in order to cause Windows to load it earlier in the boot process. By loading the driver earlier in the boot process, this issue will be avoided.
Note: Backup the Registry before performing the steps listed below.