You may need to remove client IP address ranges.
To remove client IP address ranges from the list of addresses that require authentication
In Symantec Endpoint Protection Manager, click Admin.
Select and expand the group of Enforcers.
Select the group of Gateway Enforcer appliances for which you want to edit client IP address ranges on the list of addresses that require authentication.
Under Tasks, click Edit Group Properties.
In the Gateway Settings dialog box, on the Auth Range tab, in the Client IP address range area, click the row containing the IP address that you want to remove.