Establishing a VPN Connection with an ICS Host

You should establish VPN connections on clients of an Internet Connection Sharing (ICS) Host.

Establishing a VPN connection on the ICS Host modifies the Routing Table on the ICS Host and forces all clients that try to connect to the Internet to use the VPN routing table instead of the routing table used to connect to the Internet service provider (ISP). This can create the following issues:

1. Clients may not be able to resolve the names of Internet resources and must use the Name Resolution services of the network where the ICS Host is connected using VPN. In Microsoft Internet Explorer, client computers may receive the following error message:
   Error: Page Can Not be Displayed.
   You may receive other error messages that say the VPN server can not be located when you try to establish a second VPN connection from the client.
2. Depending upon the network, all clients may be able to connect to the secure network as the same account that initially established the VPN connection. For example, if you establish a VPN connection to a corporate network on a computer running ICS, all the clients connected to the ICS Host may be able to connect to all the network resources on your corporate network.

The issues listed in this article do not occur if you establish the VPN connection on a client ICS Host computer connected to the Internet.