Three specific network questions must be asked:
Does basic connectivity exist?
Is DNS working?
Can the client and the user authenticate to the domain? (If the computer and user cannot authenticate to the domain, then the policy will not be downloaded.)
It's probably most efficient to troubleshoot network problems by starting with the last issue first. If the client and user can authenticate to the domain, then basic networking and DNS are working. If the client or the user cannot authenticate to the domain, it may seem logical to test DNS. However, there are many DNS issues that can prevent logon and Group Policy operations. Before launching extensive DNS tests, perform basic connectivity tests. If these are ...