Because the continued presence of Teefer2 on a machine after uninstalling the Symantec Endpoint Protection client or removing only the Network Threat Protection component can cause this issue, you want to determine if Teefer2 is still present on a machine.
Symptoms Complete loss of network connectivity after removing the Network Threat Protection (client firewall) component in Add / Remove Programs by means of a 'Modify' installation OR removing all elements of the Symantec Endpoint Protection client through Add / Remove Programs, Manual Uninstall or running the CleanWipe utility. All components of the Symantec Endpoint Protection client should have been removed.
Teefer2 Driver is still in the network stack.
For Symantec Endpoint Protection client versions from the original release to Symantec Endpoint Protection version 11.0.2020, right-click on Network Neighborhood, Select Properties. Right click on Local Area Connection and again select Properties. In the default Network tab look for the Teefer2 Driver. It should not be present after removing the Network Threat Protection (client firewall) component.
If the Teefer2 Driver is present, it is a defect.
Uncheck the Teefer2 Driver option and network connectivity should be restored.
For Symantec Endpoint Protection client versions 11.0.3001 or later, to determine if Teefer2 is actually present on the machine:
In the Computer Management Console, select Device Manager.
On the menu bar, click 'View' and select 'Devices by type' and 'Show hidden devices.'
Expand 'Network adapters.'
Are there any entries for Teefer2 Miniport?
If that is the case, contact Symantec Technical Support.
Provide this document number (2009011415053048) to the Support Technician.
If removing the Teefer2 components does not restore network connectivity, look in the event log for
Event ID: 20035 Source: Rasman Description: Remote Access Connection Manager failed to start because it could not create buffers. Restart the computer. Access is denied.