Any networking device positioned between a Remote Access Service (RAS) server and a RAS client. Intermediary devices are third-party devices for performing security-related tasks such as authentication, encryption, and other functions.
RAS on Microsoft Windows NT Server and on Windows 2000 Server supports intermediary devices.
An intermediary device such as a security host can be positioned between a RAS server and its modem pool. Clients connecting to the modem pool must be authenticated by the security host before they can establish a connection with the RAS server. The security host thus provides an extra layer of security for remote access to the network.
The security host might prompt the user for credentials, or the user might be required to use a security card to gain access to the network.
Graphic I-8. A security host as an intermediary device between a RAS server and a client.
Once you have configured RAS on Windows NT Server to work with intermediary devices such as third-party security hosts, you must then configure the client to work with the device. You can typically do this by activating terminal mode on the client so that it can respond to the special prompts issued by the device.