Microsoft Proxy Server

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Definition of Microsoft Proxy Server in the Network Encyclopedia.

What was Microsoft Proxy Server?

Microsoft Proxy Server was a firewall and content-caching server that provided a secure gateway to the Internet with high response time. Microsoft Proxy Server, was part of the Microsoft BackOffice family of products, was the first firewall product to include high-performance content caching and the first content-caching server to provide firewall support.

Proxy Server includes the following features:

  • Firewall support through application layer proxy, circuit layer proxy, and dynamic packet filtering.
  • Real-time alerting and logging features that enable administrators to detect and track attacks on their networks.
  • Array-based and hierarchical content caching, including support for Caching Array Routing Protocol (CARP).
  • Support for reverse proxying, which causes Proxy Server to impersonate a Web server to outside users and enables it to fulfill requests for Web content from its cache and forward requests to the real Web server only when needed. Reverse proxying is supported only for Hypertext Transfer Protocol (HTTP).
  • Support for reverse hosting, which lets any server sitting behind Proxy Server publish to the Internet by having Proxy Server simulate virtual roots on a Web server and then redirect requests to a Web server. Reverse hosting is supported only for HTTP.
  • Support for server proxying, which allows Proxy Server to listen for incoming packets that are destined for computers on the secured network behind the Proxy Server and then forward these packets as appropriate to other servers. Server proxying is a circuit-layer service and works with a wide variety of application layer protocols.
  • Integration with Microsoft Windows NT administrative tools.
  • HTML-based administration and command-line management using scripting.
  • Support for SOCKS v4.3 support, HTTP 1.1, File Transfer Protocol (FTP) caching, and Secure Sockets Layer (SSL) tunneling.
  • Installable third-party components for virus scanning, JavaScript and ActiveX filtering, and site blocking.

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How it Works

Proxy Server provides three basic types of proxy services: Web Proxy, Winsock Proxy, and SOCKS Proxy. These can all work together with dynamic packet filtering. The following table compares these proxy services.

Features of Microsoft Proxy Server

ItemWeb ProxyWinsock ProxySOCKS Proxy
Security layer (type of proxy)Application layerCircuit layerCircuit layer
Protocols supportedHTTP, FTP, Gopher, HTTPSManyMany
Client supportAny CERN-based browserWindowsMany
Special client software neededNoYes (included)Yes (included)
Cacheable contentYesNoNo
Dynamic packet filter supportYesYesYes

See also: Proxy Server