Windows 2003 introduced the concept of an application partition that facilitated two unique places where DNS zones can be stored.Windows 2003 and Windows Server 2008 store zone information in either the Domain DNSZones or Forest DNSZones of an application directory partition.VPN clients will not be able to resolve DNS host names on the internal network if they are not assigned a DNS server address by the ISA Server firewall/VPN server.In most cases, the VPN client already has a DNS server address assigned to it.Zone VPN Client and install the latest build of Trust. If you still unable to rid of this problem after performing steps above please try In order to prevent problems with cooperation between your antivirus/firewall/anti-malware software and Trust.Zone VPN Client we strongly recommend adding Trust.Previously, I covered installing the DNS role in Windows Server 2012.Once installed, managing the role is very similar to how management was done in Windows Server 2003 through 2008 R2. DNS is one of the most important services in Windows Servers, as with most other platforms. To get into the DNS Manager in 2012 Server, first open Server Manager (you might get sick of using this tool in Server 2012, similar to how my Mac Server brethren have gotten tired of it in Lion and Mountain Lion Servers.
Even if the DNS component had not been installed and running on a specific DC, this same DC would still have DNS zone information replicated to its domain partition.
However, that DNS server address does not resolve names on the corporate network because that DNS server is intended to resolve names on the network the VPN client computer is attached to before connecting to the ISA firewall/VPN server, or to resolve only Internet host names.
The VPN client that cannot resolve internal network names may have been assigned an incorrect DNS server address.
This problem in most cases may appear on Windows 10 but sometimes may also have place on Windows 7, Windows Xp and Windows Vista operating systems. Zone VPN Client stops working on your Windows 10 you may need to turn off Driver Signature Enforcement and reinstall client.
This is happening because Windows 10 has changed the way it verifies driver signatures.