Chapter 1 - MS TCP/IP And Related Services For Windows NT

Archived content. No warranty is made as to technical accuracy. Content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.

The Transmission Control Protocol/Internet Protocol (TCP/IP) suite is a standard set of networking protocols that govern how data passes between networked computers. With TCP/IP you can communicate with Windows NT platforms, with devices that use other Microsoft networking products, and with non-Microsoft systems (such as UNIX systems). TCP/IP is the primary protocol of the Internet and the World Wide Web. It is also the primary protocol for many private internetworks, which are networks that connect local area networks (LANs) together.

For procedural information about installing and configuring TCP/IP under Windows NT, see the online Help. For more detailed information about TCP/IP and its integration with Windows NT and other networking products, see the Microsoft Windows NT Resource Kit Networking Guide.

Benefits of Using TCP/IP

Microsoft TCP/IP for Windows NT Server and Windows NT Workstation offers the following advantages:

  • A standard, routable networking protocol that is the most complete and accepted protocol available. All modern operating systems offer TCP/IP support, and most large networks rely on TCP/IP for much of their network traffic. 

  • A technology for connecting dissimilar systems. Many standard connectivity utilities are available to access and transfer data between dissimilar systems, including File Transfer Protocol (FTP) and Terminal Emulation Protocol (Telnet). Several of these standard utilities are included with Windows NT. 

  • The enabling technology necessary to connect Windows NT to the global Internet. TCP/IP, Point to Point Protocol (PPP), Point to Point Tunneling Protocol (PPTP), and Windows Sockets provide the foundation needed to connect and use Internet services. 

  • A robust, scalable, cross-platform, client-server framework. Microsoft TCP/IP supports the Windows Sockets interface, which is a Windows-based implementation of the widely used Berkeley Sockets interface for network programming. 

Core Technology and Third-Party Add-Ons

Microsoft TCP/IP is a full-featured implementation of the protocol suite and related services. It includes the following:

  • Core TCP/IP protocols, including the Transmission Control Protocol (TCP), Internet Protocol (IP), User Datagram Protocol (UDP), Address Resolution Protocol (ARP), and Internet Control Message Protocol (ICMP). This suite of Internet protocols dictates how computers communicate and how networks are interconnected. Support is also provided for Point to Point Protocol (PPP), Point to Point Tunneling Protocol (PPTP), and Serial-Line IP (SLIP), which are protocols used for dial-up access to TCP/IP networks, including the Internet. 

  • Support for network programming interfaces such as Windows Sockets, remote procedure call (RPC), NetBIOS, and network dynamic data exchange (Network DDE). 

  • Basic TCP/IP connectivity utilities, including finger, ftp, lpr, rcp, rexec, rsh, telnet, and tftp. These utilities allow users running Windows NT to interact with and use resources on non-Microsoft hosts (such as those running UNIX). 

  • TCP/IP diagnostic tools, including arp, hostname, ipconfig, lpq, nbtstat, netstat, ping, route, and tracert. Use these utilities to detect and resolve TCP/IP networking problems. 

  • Services and related administrative tools, including the Internet Information Server for setting up Internet or Intranet Web sites, Dynamic Host Configuration Protocol (DHCP) service for automatically configuring TCP/IP on computers running Windows NT, Windows Internet Name Service (WINS) for dynamically registering and querying NetBIOS computer names on an internetwork, Domain Name System (DNS) Server service for registering and querying DNS domain names on an internetwork, and TCP/IP printing for accessing printers connected to computers running UNIX or connected directly to the network with a dedicated network adapter. 

  • Simple Network Management Protocol (SNMP) agent. This component allows a computer running Windows NT to be monitored remotely with management tools such as Sun® Net Manager or HP® Open View. Microsoft TCP/IP also includes SNMP support for DHCP and WINS servers. 

  • The server software for simple network protocols, including Character Generator, Daytime, Discard, Echo, and Quote of the Day. These protocols allow a computer running Windows NT to respond to requests from other systems that support these protocols. 

  • Path MTU Discovery, which provides the ability to determine the datagram size for all routers between Windows NT-based computers and any other systems on the WAN. Microsoft TCP/IP also supports the Internet Group Management Protocol (IGMP), which is used by workgroup software products. 

Figure 1-1 shows the elements of Microsoft TCP/IP alongside the variety of additional applications and connectivity utilities provided by Microsoft and other third-party vendors.


Figure 1-1 Microsoft TCP/IP Core Technology and Third-party Add-ons 

Microsoft TCP/IP for Windows NT does not include a complete suite of TCP/IP connectivity utilities or server services (daemons). Many such applications and utilities—available in the public domain or from third-party vendors—are compatible with Microsoft TCP/IP.

Note For computers running Windows for Workgroups, you can install Microsoft TCP/IP-32. For computers running MS-DOS, you can install the Microsoft Network Client for MS-DOS. Both are available on the Windows NT Server compact disc. For installation information, see the Windows NT Server Concepts and Planning Guide.

Supported Standards

Requests for Comments (RFCs) are an evolving series of reports, proposals for protocols, and protocol standards used by the Internet community. TCP/IP standards are defined in RFCs published by the Internet Engineering Task Force (IETF) and other working groups. Table 1.1 lists the RFCs supported in this version of Microsoft TCP/IP (and Microsoft Remote Access Service).




User Datagram Protocol (UDP)


Trivial File Transfer Protocol (TFTP)


Internet Protocol (IP)


Internet Control Message Protocol (ICMP)


Transmission Control Protocol (TCP)


Fault Isolation and Recovery


Address Resolution Protocol (ARP)


Telnet Protocol (TELNET)


Echo Protocol (ECHO)


Discard Protocol (DISCARD)


Character Generator Protocol (CHARGEN)


Quote of the Day Protocol (QUOTE)


Daytime Protocol (DAYTIME)


IP over Ethernet

919, 922

IP Broadcast Datagrams (broadcasting with subnets)


Internet Standard Subnetting Procedure


File Transfer Protocol (FTP)

1001, 1002

NetBIOS Service Protocols

1034, 1035

Domain Name System (DNS)


IP over Token Ring


Transmission of IP over Serial Lines (IP-SLIP)


Internet Group Management Protocol (IGMP)

1122, 1123

Host Requirements (communications and applications)


Point to Point Protocol (PPP)


Compressing TCP/IP Headers for Low-Speed Serial Links


Simple Network Management Protocol (SNMP)


Line Printer Daemon Protocol


IP over FDDI


Path MTU Discovery




IEEE 802.5 Token Ring MIB (MIB-II)


PPP Internet Protocol Control Protocol (IPCP)


PPP Authentication Protocols


An Architecture for IP Address Allocation with CIDR


Classless Inter-Domain Routing (CIDR): An Address Assignment and Aggregation Strategy


DHCP Options and BOOTP Vendor Extensions 1


Interoperation Between DHCP and BOOTP


Dynamic Host Configuration Protocol (DHCP)


Clarifications and Extensions for the Bootstrap Protocol 2


Requirements for Point to Point Protocol (PPP)


Point to Point Protocol (PPP)


PPP in High-level Data Link Control (HDLC) Framing


PPP Internetwork Packet Exchange Control Protocol (IPXCP)


IPX Header Compression


Link Control Protocol (LCP) Extensions

Draft RFCs

NetBIOS Frame Control Protocol (NBFCP); PPP over ISDN; PPP over X.25; Compression Control Protocol

1 The Microsoft DHCP server does not support BOOTP. BOOTP requests are silently ignored. However, a DHCP server and a BOOTP server can coexist. 

2 Windows NT Server can be configured to act as a BOOTP relay agent. 

Note For details on retrieving RFCs by means of FTP or email, send an email message to "rfc-info@ISI.EDU" with the subject "getting rfcs" and the message body "help: ways_to_get_rfcs".



This section summarizes how Microsoft TCP/IP works with Windows NT to provide enterprise internetworking solutions. For a more detailed discussion of these points, see the Microsoft Windows NT Resource Kit Networking Guide.

Using TCP/IP for Scalability

TCP/IP delivers a scalable internetworking technology widely supported by hardware and software vendors.

When TCP/IP is used as the enterprise-networking protocol, the Windows-based networking solutions from Microsoft can be used on an existing internetwork to provide client and server support for TCP/IP and connectivity utilities. These solutions include

  • Microsoft Windows NT Workstation, with enhancements to support wide area networks (WAN), TCP/IP printing, FTP, Telnet, DHCP, WINS, and DNS client software, Windows Sockets, and extended LMHOSTS file. 

  • Microsoft Windows NT Server, with the same enhancements as Windows NT Workstation, plus Internet Information Server, DHCP Server, WINS Server, and DNS Server software. 

  • Microsoft Windows 95, with enhancements to support wide area networks (WAN), DHCP, WINS, and DNS client software, extended LMHOSTS file, and Windows Sockets. 

  • Microsoft TCP/IP-32 for Windows for Workgroups, with Windows Sockets support, can be used to provide access for Windows for Workgroups computers to Windows NT, LAN Manager, and other TCP/IP systems. Microsoft TCP/IP-32 includes DHCP, WINS and DNS client software. 

  • Microsoft LAN Manager—including both client and server support for Windows Sockets—and MS-DOS–based connectivity utilities. The Microsoft Network Client 2.0 software on the Windows NT Server compact disc includes new Microsoft TCP/IP support with DHCP and WINS clients. 

As shown in Figure 1-2, the current version of TCP/IP for Windows NT also supports IP routing in systems with multiple network adapters attached to separate physical networks (multihomed systems).


Figure 1-2 TCP/IP for Windows NT Supports IP Routing for Multihomed Systems 

Using TCP/IP in Heterogeneous Networks

Because most modern operating systems support TCP/IP protocols, heterogeneous computers on an internetwork can use simple networking applications and utilities to share information. TCP/IP enables Windows NT to communicate with many non-Microsoft systems, including

  • Internet hosts 

  • Apple® Macintosh® systems 

  • IBM mainframes 

  • UNIX systems 

  • Open VMS™ systems 

  • Printers with network adapters connected directly to the network 

As shown in Figure 1-3, Microsoft TCP/IP provides a framework for interoperable heterogeneous networking. The modular architecture of Windows NT networking with its transport-independent services contributes to the strength of this framework. For example, Windows NT supports the following transport protocols:


Figure 1-3 Microsoft TCP/IP Connectivity 

  • IPX/SPX for use in NetWare environments, using the Microsoft NWLink transport. Besides providing interoperability with NetWare networks, IPX/SPX is a fast LAN transport for Windows-based networking as well. 

  • TCP/IP for internetworks based on IP technologies. TCP/IP is the preferred transport for internetworks and provides interoperability with UNIX and other TCP/IP-based networks. 

  • NetBEUI as the protocol for local area networking on smaller networks and compatibility with existing LAN Manager and IBM LAN Server networks. 

  • AppleTalk for connecting to and sharing resources with Macintosh systems. 

Note Transport protocols (such as DECnet and OSI) from third-party vendors can also be used by Windows NT networking services.

Using TCP/IP with Third-Party Software

TCP/IP is a common denominator for heterogeneous networking, and Windows Sockets is a standard used by application developers. Together they provide a framework for cross-platform client-server development.

The Windows Sockets standard defines a networking API that developers use to create applications for the entire family of Microsoft Windows operating systems. Windows Sockets is an open standard that is part of the Microsoft Windows Open System Architecture (WOSA) initiative. It is a public specification based on Berkeley UNIX sockets, which means that UNIX applications can be quickly ported to Microsoft Windows and Windows NT. Windows Sockets provides a single standard programming interface supported by all major vendors implementing TCP/IP for Windows systems.

The Windows Sockets standard ensures compatibility with Windows-based TCP/IP utilities developed by many vendors. This includes third-party applications for X Windows, sophisticated terminal emulation software, NFS, electronic mail packages, and more. Because Windows NT offers compatibility with 16-bit Windows Sockets, applications created for Windows 3.x Windows Sockets run on Windows NT without modification or recompilation.

For example, third-party applications for X Windows provide strong connectivity solutions by means of X Windows servers, database servers, and terminal emulation. With such applications, a computer running Windows NT can work as an X Windows server while retaining compatibility with applications created for Windows NT, Windows 95, Windows 3.x, and MS-DOS on the same system. Other third-party software includes X Windows client libraries for Windows NT, which enable developers to write X Windows client applications on Windows NT that can be run and displayed remotely on X Windows servers.

The TCP/IP utilities for Windows NT use Windows Sockets, as do 32-bit TCP/IP applications developed by third parties. Windows NT also uses the Windows Sockets interface to support Services for Macintosh and IPX/SPX in NWLink. Under Windows NT, 16-bit Windows-based applications created under the Windows Sockets standard will run without modification or recompilation. Most TCP/IP users will use programs that comply with the Windows Sockets standard (such as ftp or telnet) or third-party applications.

The Windows Sockets standard allows a developer to create an application with a single common interface and a single executable that can run over many TCP/IP implementations. Windows Sockets is designed to:

  • Provide a familiar networking API to developers using Windows NT, Windows 95, Windows for Workgroups, or UNIX. 

  • Offer binary compatibility between vendors for heterogeneous Windows-based TCP/IP stacks and utilities. 

  • Support both connection-oriented and connectionless protocols. 

Typical Windows Sockets applications include graphic connectivity utilities, terminal emulation software, Simple Mail Transfer Protocol (SMTP) and electronic mail clients, network printing utilities, SQL client applications, and corporate client-server applications.

Specifications for Windows Sockets are available on numerous Internet sites such as, the Microsoft Network (MSN), and CompuServe.