WINDOWS 1002000 PROFESSIONAL RESOURCE KIT [Electronic resources] نسخه متنی

Overview of Windows 2000 TCP/IP

Transmission Control Protocol/Internet Protocol (TCP/IP) provides communication across interconnected networks that use diverse hardware architectures and various operating systems. TCP/IP can be used to communicate with computers running Windows 2000, with devices using other Microsoft networking products, or with non-Microsoft systems such as UNIX.

TCP/IP in Windows 2000 Professional improves upon the functionality that TCP/IP provided in Microsoft® Windows NT® Workstation version 4.0. Table 22.1 shows Windows 2000 TCP/IP features:

Table 22.1 Features of TCP/IP in Windows 2000

What's New in Windows 2000 TCP/IP

TCP/IP in Windows 2000 builds upon the networking strengths found in Windows NT Workstation 4.0 and Microsoft® Windows® 98. These improvements result in a scalable networking platform that can be implemented in a variety of environments, from a small office/home office configuration, to a powerful workstation within a multidomain enterprise.

The improvements made in Windows 2000 Professional can be categorized into five areas, each presented in this chapter:

Address assignment and IP packet handling

Name resolution

IP security

Quality of Service (QoS)

TCP Performance

Address Assignment and IP Packet Handling

Windows 2000 makes setting up small office/home office (SOHO) configurations easier through two new features. Automatic Private IP Addressing (APIPA) assigns an IP address and subnet mask to a Windows 2000 Professional computer if a DHCP server is not available. Access to outside networks is also facilitated through Internet Connection Sharing (ICS), which translates private IP addresses to a single public IP address, which can access other intranets or the Internet.

Configuration of large enterprise networks is facilitated through the addition of several new features. ICMP Router Discovery automatically configures a default gateway for a Windows 2000 Professional host. ICMP Router Discovery allows clients to discover gateways dynamically. TCP/IP over ATM permits the use of Asynchronous Transfer Mode (ATM) adapters connected to ATM-based, packet-switched networks.

Name Resolution

Windows 2000 Professional includes several modifications to its IP address/name resolution process to make it an Internet-ready client. DNS is the default name resolution method for the Windows 2000 environment, replacing NetBIOS as the default name management method for Windows-based domains.

To facilitate maintenance of DNS record databases, Microsoft® Windows® 2000 Server supports dynamic update, as specified in Request for Comments (RFC) 2136. Windows 2000 Professional provides dynamic update of DNS servers that are compliant with RFC 2136, providing address and domain name updates directly or through a DHCP server.

A number of additional improvements have been made in DNS, including support for an extended character set (RFC 2181), client-side caching, connection-specific domain names, and improved performance through subnet prioritization.

IP Security

Windows 2000 provides network security through the implementation of IP security (IPSec). IPSec is a set of rules and protocols defined by the Internet Engineering Task Force (IETF) that provide encryption, data authentication, and data integrity at the packet level. These features are enabled below the network layer, requiring no change to the existing network and application infrastructure to deploy IP security. Local and domain-based IPSec policies can be created to implement IP security.

Quality of Service

As multimedia-rich applications such as video conferencing and video-on-demand become more pervasive within a network, the issues of network bandwidth and the quality of data transmission become more critical. Windows 2000 Professional addresses this through its implementation of Quality of Service (QoS), a set of specifications that determine the network requirements needed by a multimedia or qualitative application. Windows 2000 Professional also implements the Resource Reservation Protocol (RSVP), which allows an application or service to reserve a specific amount of bandwidth needed for data transmission.

TCP Performance

Windows 2000 Professional includes enhancements to TCP that improve the performance of TCP/IP-based networks. Larger default TCP receive window size increases performance on high-speed networks. Window scaling, as documented in RFC 1323, allows the use of a very large TCP receive window in high bandwidth, high delay environments. To improve performance in high-loss environments such as the Internet, selective acknowledgments (SACKs) enables a receiving host to selectively acknowledge only the data it has received.

Comparison of Windows 2000 Features

Table 22.2 displays the new features implemented in Windows 2000, compared to Windows 98 and Microsoft® Windows NT® version 4.0.

Table 22.2 Comparison of Windows 2000 TCP/IP Features