Knowledgebase: LAN Clients
Problems with a NAT connection
Posted by Adrien de Croy (Import) on 24 January 2007 07:54 PM
NAT offers a simple method of connecting LAN clients to the internet through the WinGate server. NAT should work where other connection methods fail because it simply routes the client connections out through WinGate.

As long as you have NAT set up properly it should require very little configuration or management. If you are having problems with your NAT connections you can check the following:

1. Is the Extended Networking driver installed?

When you install WinGate you can decide whether you want to install the "Extended Networking Service" (ENS). ENS is required for NAT, VPNs, Firewall, Routing etc. If you did not install ENS when you installed WinGate then you won't have an Extended Networking menu on the system tab in GateKeeper, you will need to reinstall WinGate to add ENS services.

The screenshot below shows the Extended Networking menu, with the status of the driver as "installed and active". In the Extended Networking menu there is an option to enable/disable NAT, this should be checked to allow NAT connections from the LAN.

Check you have NAT

2. Have your network adapters been correctly identified by WinGate?

NAT connections require an internal and an external adapter in the WinGate server to work properly. Often if you're behind a DSL router your external adapter will have a private IP address, so you may need to change the adapter settings in WinGate.

WinGate determines whether an adapter is internal or external based on the IP address of the adapter. An adapter with a public IP address is seen as external and firewalled, an adapater with a private IP address is seen as internal and services are bound to this adapter.

Therefore the network adapter pointing at the Internet should be marked as "External" and the network card pointing towards your private network should be marked as "Internal"; as shown in the image below. If you need to change the adapter usage just double click the adapter and choose the appropriate setting.

Check your network cards / modems are detected by WinGate correctly

3. Network settings

Having more than one default gateway in your WinGate server can cause you routing problems and we recommend that you don't do this. Your WinGate server should have its network cards configured as below. We have chosen the 192.168.0.* subnet for our example, but any private IP address range is fine.

WinGate server:

External adapter:
IP address : (Assigned by ISP/router)
Subnet mask: (Assigned by ISP/router)
default gateway: (Assigned by ISP/router)
DNS server : (Assigned by ISP/router)

Internal adapter:
IP address :
Subnet mask:
Defaulte gateway: (left blank)
DNS server : (left blank)

Your LAN clients should have an IP address on the same subnet as the WinGate server, ie 192.168.0.*. They should have their default gateway and DNS server pointing at the WinGate server.

LAN Client:
IP address :
Subnet mask:
Default gateway:
DNS server :

Subsequent LAN clients will be on the same subnet, but their IP address will change.

For more information on setting up NAT on the clients please see this Knowledge Base article.

Additional considerations:

If you are running third party security applications on the WinGate server then you may see a driver conflict with the WinGate driver. For the purposes of testing you can uninstall the third party applications and see if that solves the problem. If it does please contact support for further information by submitting a support request here

If you are using Windows XP(SP2)/Windows 2003 on your LAN, then we recommend turning off the Windows Firewall. The only way to make sure it stays off is to disable it from the services applet.

If you have a Realtek 8029 network card please navigate to (Windows) Start menu-->Programs-->WinGate-->Advanced Options-->Hardware Specific-->Check the box "Realtek 8029 Chipset in use".
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