Tài liệu Module 5: Implementing Name Resolution doc

Contents Overview 1 Introduction to Name Resolution 2 NetBIOS Name Resolution 4 Host Name Resolution 11 Configuring Name Resolution for Client Computers 16 Troubleshooting Name Resolution 22 Lab A: Configuring a Client Computer for Name Resolution 29 Review 39 Module 5: Implementing Name Resolution Information in this document, including URL and other Internet Web site references, is subject to change without notice. Unless otherwise noted, the example companies, organizations, products, domain names, e-mail addresses, logos, people, places, and events depicted herein are fictitious, and no association with any real company, organization, product, domain name, e-mail address, logo, person, places or events is intended or should be inferred. Complying with all applicable copyright laws is the responsibility of the user. Without limiting the rights under copyright, no part of this document may be reproduced, stored in or introduced into a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise), or for any purpose, without the express written permission of Microsoft Corporation. Microsoft may have patents, patent applications, trademarks, copyrights, or other intellectual property rights covering subject matter in this document. Except as expressly provided in any written license agreement from Microsoft, the furnishing of this document does not give you any license to these patents, trademarks, copyrights, or other intellectual property.  2001 Microsoft Corporation. All rights reserved. Microsoft, MS-DOS, Windows, Windows NT, <plus other appropriate product names or titles. The publications specialist replaces this example list with the list of trademarks provided by the copy editor. Microsoft, MS-DOS, Windows, and Windows NT are listed first, followed by all other Microsoft trademarks listed in alphabetical order. > are either registered trademarks or trademarks of Microsoft Corporation in the U.S.A. and/or other countries. <The publications specialist inserts mention of specific, contractually obligated to, third-party trademarks, provided by the copy editor> The names of actual companies and products mentioned herein may be the trademarks of their respective owners. Module 5: Implementing Name Resolution iii Instructor Notes This module provides students with the knowledge and skills required to configure, manage and troubleshoot name resolution. Students will learn the concept of name resolution and the difference between network basic input/output (NetBIOS) and Transmission Control Protocol (TCP) host names. They will learn how to configure a computer to use NetBIOS and Domain Name System (DNS) name resolution services, and how to use Windows utilities to troubleshoot name resolution problems. After completing this module, students will be able to: ! Describe the key concepts of name resolution. ! Describe the differences between NetBIOS and host names. ! Explain the various mechanisms that are used to perform name resolution. ! Configure a computer to manage name resolution services. ! Troubleshoot name resolution problems. Materials and Preparation This section provides the materials and preparation tasks that you need to teach this module. Required Materials To teach this module, you need the following Microsoft ® PowerPoint ® file 2126A_05.ppt. Preparation Tasks To prepare for this module: ! Read all of the materials for this module. ! Complete the lab. Presentation: 60 Minutes Lab: 60 Minutes iv Module 5: Implementing Name Resolution Module Strategy Use the following strategy to present this module: ! Introduction to Name Resolution In this topic, you will explain the need for resolution of names to Internet Protocol (IP) addresses, and briefly describe the two forms of name-to-IP- address resolution. ! NetBIOS Name Resolution In this topic, you explain how to identify when NetBIOS names are used. You will outline the role of the Lmhosts file, Windows Internet Name Service (WINS), and the NetBIOS name cache in resolving NetBIOS names. ! Host Name Resolution In this topic, you will explain how to identify the situations when host names are used. You will also outline the role of the Hosts file, DNS, and the DNS resolver cache in resolving host names. ! Configuring Name Resolution for Client Computers In this topic, you will explain how to configure a variety of Microsoft client operating systems to use WINS and DNS. ! Troubleshooting Name Resolution In this topic, you will describe some of the command line utilities that can be used when troubleshooting name resolution. Module 5: Implementing Name Resolution 1 Overview ! Introduction to Name Resolution ! NetBIOS Name Resolution ! Host Name Resolution ! Configuring Name Resolution for Client Computers ! Troubleshooting Name Resolution In Microsoft ® Windows ® 2000 and Microsoft Windows XP, the primary means for client computers to locate and communicate with other computers on an Internet Protocol (IP) network is by using the Domain Name System (DNS). DNS is a distributed database that is used in IP networks to translate, or resolve, computer names into IP addresses However, clients using previous versions of Windows, such as computers running Microsoft Windows 98 or Microsoft Windows NT ® version 4.0, also use network basic input/output (NetBIOS) names for network communication. As a result, these clients require a method of resolving NetBIOS names to IP addresses. You can install Windows Internet Name Service (WINS) to register NetBIOS computer names and resolve them to IP addresses. Implementing WINS in a Windows 2000 network ensures that clients that use a previous version of Windows can locate and communicate with network resources as needed. Windows 2000 and Windows XP use DNS, but they support NetBIOS to remain backward-compatible with older networks. After completing this module, you will be able to: ! Describe various types of names and the concept of name resolution. ! Describe NetBIOS and Transmission Control Protocol/Internet Protocol (TCP/IP) Host Name Resolution. ! Explain the various methods of resolving NetBIOS names. ! Explain the various methods of resolving host names. ! Configure your computer to use either type of name resolution. ! Troubleshoot name resolution problems. Topic Objective To provide an overview of the module topics and objectives. Lead-in In this module, you will learn about name resolution, both of NetBIOS names and TCP host names. You will learn how to configure your computer for both kinds of name resolution, and how to troubleshoot problems. 2 Module 5: Implementing Name Resolution Introduction to Name Resolution ! The Process of mapping a name to an IP address ! Types of names: " NetBIOS name " TCP/IP host name ! Name resolution methods are configurable Name resolution is the process of mapping a textual computer name to a numeric IP address. NetBIOS Name Resolution NetBIOS name resolution maps a NetBIOS name to an IP address. Microsoft TCP/IP can use any of the following methods to resolve NetBIOS names: Standard methods of resolution Description NetBIOS name cache The local cache containing the NetBIOS names that the local computer recently resolved. NetBIOS name server (NBNS) A server implemented under RFC 1001, Protocol standard for a NetBIOS service on a TCP/UDP transport: Concepts and methods and RFC 1002, Protocol standard for a NetBIOS service on a TCP/UDP transport: Detailed specifications, to provide name resolution of NetBIOS computer names. The Microsoft implementation of this standard is WINS. Local broadcast A broadcast on the local network for the IP address of the destination NetBIOS name. Topic Objective To define name resolution and provide an overview of the various methods used to resolve names. Lead-in To reach a remote computer on a network, its name must first be resolved to an IP address. Module 5: Implementing Name Resolution 3 Additional Microsoft methods of resolution Description Lmhosts file A local text file that maps IP addresses to the NetBIOS computer names of Windows networking computers on remote networks. Hosts file A local text file in the same format as the 4.3 Berkeley Software Distribution (BSD) UNIX\etc\hosts file. This file maps host names to IP addresses. This file is typically used to resolve host names for TCP/IP utilities. DNS A server that maintains a database of IP address/computer name (host name) mappings. Host Name Resolution Microsoft TCP/IP can use any of the following methods to resolve host names. The methods that Windows 2000 can use to resolve a host name are configurable. Standard methods of resolution Description Local host name The configured host name for the computer. This name is compared to the destination host name. Host file A local text file in the same format as the 4.3 Berkeley Software Distribution (BSD) UNIX\etc\hosts file. This file maps host names to IP addresses. This file is typically used to resolve host names for TCP/IP utilities. DNS server A server that maintains a database of IP address/computer name (host name) mappings. Additional Microsoft methods of resolution Description NBNS A server implemented under RFC 1001, Protocol standard for a NetBIOS service on a TCP/UDP transport: Concepts and methods and RFC 1002, Protocol standard for a NetBIOS service on a TCP/UDP transport: Detailed specifications, to provide name resolution of NetBIOS computer names. The Microsoft implementation of this standard is WINS. Local broadcast A broadcast on the local network for the IP address of the destination NetBIOS name. Lmhosts file A local text file that maps IP addresses to the NetBIOS computer names of Windows networking computers on remote networks. 4 Module 5: Implementing Name Resolution # ## # NetBIOS Name Resolution ! What Is a NetBIOS Name? ! NetBIOS Name Cache ! Name Resolution Using Lmhosts ! Name Resolution Using WINS The NetBIOS name is a computer name used with some Windows operating systems to identify computers on a network. To establish communications with another computer, the name must be resolved to an IP address. Specific mechanisms exist for the resolution of NetBIOS names. In Windows 2000 and most of the earlier networked versions of Windows, these are the Lmhosts file and WINS. Topic Objective To define NetBIOS names and examine methods for resolving them. Lead-in NetBIOS names have their own resolution methods. Module 5: Implementing Name Resolution 5 What is a NetBIOS Name? ! NetBIOS names are 16-byte addresses that uniquely identify a process for network identification ! NetBIOS names are registered dynamically and can be: " Used only once in a network " Registered as unique names or group names ! Use browsing to locate shared resources on the network NetBIOS names are a more limiting alternative for naming computers to DNS names. Windows 2000 can use DNS names for most functions, but a NetBIOS name resolution method must exist on any network with computers that are running earlier versions of Windows and applications that depend on NetBIOS names. NetBIOS names are 16 bytes in length, and the NetBIOS namespace has only one level. This means that NetBIOS names can be used only once in a network. In contrast, the DNS namespace has multiple levels because DNS uses a fully qualified domain name (FQDN), which combines the host name with the name of its domain. NetBIOS Name Registration NetBIOS names are registered dynamically when computers and services start and when users log on. A NetBIOS name can be registered as a unique name, which maps to a single address, or as a group name, which maps to multiple addresses. Because multiple services that are running on the same computer can register a computer’s NetBIOS name, several NetBIOS name registrations can be generated for the same computer name. The registered name is the 15-character computer name plus a sixteenth character. The sixteenth character uniquely identifies each service that uses the computer name to build its NetBIOS name. Slide Objective To list the characteristics of NetBIOS names. Lead-in The NetBIOS name is the name assigned to a computer during installation. Delivery Tip Emphasize that other NetBIOS-based computers, such as computers running previous versions of Windows, also use NetBIOS names. Key Point NetBIOS names are registered dynamically when computers and services start and when users log on. Important 6 Module 5: Implementing Name Resolution Example of NetBIOS Name Registration An example of a service that uses a NetBIOS name is the Server service in Windows 2000, which provides file and printer sharing. When you start your computer, the service registers a unique NetBIOS name that is based on the computer name. The registered name is the 15-character computer name plus a sixteenth character of 0x20. The sixteenth character uniquely identifies the Server service. When you attempt to connect to a shared folder by using a NetBIOS name, a name query is initiated to search for the NetBIOS name of the Server service. Communication is established when the NetBIOS name is located, and then you can connect to the server on which the shared folder is stored. Browsing Windows 2000 creates lists of registered NetBIOS names to enable users to locate computers that contain shared resources on the network. The process of building these lists is called browsing. To access these shared resources: 1. Open My Network Places, and then double-click Entire Network. 2. Click Entire contents. 3. Double-click Microsoft Windows Network. 4. Double-click the appropriate domain or workgroup, and then double-click the name of computer on which the resource is stored. Open Network Neighborhood to access browsing information on computers running earlier versions of Windows. For more information about browsing, see Appendix XX, Computer Browser Service, under Additional Reading on the Web page on the Student Materials compact disc, and the appendix, Windows 2000 Browser Service, in the TCP/IP Core Networking Guide in the Microsoft Windows 2000 Server Resource Kit. Delivery Tip Describe the browsing process, and demonstrate the procedure for accessing shared resources. Note Key Point Open Network Neighborhood to access browsing information on computers running earlier versions of Windows. [...]... WINS server Module 5: Implementing Name Resolution 11 # Host Name Resolution Topic Objective To define host names and examine methods for resolving them ! What Is a Host Name? Lead-in ! DNS Resolver Cache ! Name Resolution Using Hosts ! Name Resolution Using DNS Host names have their own resolution methods DNS is the Windows 2000 standard for naming host computers DNS provides a hierarchical namespace.. .Module 5: Implementing Name Resolution 7 NetBIOS Name Cache Topic Objective To explain the function of the NetBIOS name cache Lead-in To improve performance, a cache is maintained of recently resolved names ! A local cache containing most recently resolved NetBIOS names ! Name resolution searches the cache first When a user initiates a Windows command, such as net use, the NetBIOS name resolution. .. configuration method varies according to the Windows operating system in use You can configure your computer to use WINS name resolution or DNS name resolution Your choice of WINS name resolution or DNS name resolution depends on the version of Windows that you are running Module 5: Implementing Name Resolution Configuring Client Computers to Use WINS Topic Objective To show how to configure your client computer... 2 On the Computer Name tab, click Change 3 In the Computer Name Changes dialog box, click More 4 In the DNS Suffix and NetBIOS Computer Name dialog box, in the Primary DNS suffix of this computer dialog box, type the DNS domain name for the computer 22 Module 5: Implementing Name Resolution # Troubleshooting Name Resolution Topic Objective To show how to diagnose problems in name resolution ! Using... utility, see Module 8, “Managing DNS,” in Course 2126A, Managing a Microsoft Windows 2000 Network Environment (Prerelease) 28 Module 5: Implementing Name Resolution Using net and nbtstat to Manage NetBIOS Name Resolution Topic Objective To show how to use the net and nbtstat commands to manage NetBIOS name resolution Lead-in If you have problems with NetBIOS name resolution, check the NetBIOS name information,... command 14 Module 5: Implementing Name Resolution Name Resolution Using Hosts Slide Objective To explain how a host name is resolved to an IP address by using the Hosts file ping HostB ping HostB Lead-in Unlike the Lmhosts file, which is used for remote hosts only, the Hosts file maps host names of both local and remote hosts to their IP addresses HostB = 131.107.7.29 1 1 Name Resolution Hostname = HostA... A host name always corresponds to an IP address that is stored in a Hosts file or in a database on a DNS or NetBIOS name server Windows 2000 also uses the Lmhosts file to map host names to IP addresses ! The Hostname utility displays the host name that is assigned to your system By default, the host name is the same as the computer name of your Windows computer Module 5: Implementing Name Resolution. .. process begins The NetBIOS name cache is checked for the NetBIOS name/ IP address mapping of the destination host If the NetBIOS name is not found in the cache, the Windows client attempts to determine the IP address of the destination host by using other methods You can view the NetBIOS name cache by using the nbtstat –c command 8 Module 5: Implementing Name Resolution Name Resolution Using Lmhosts... namespace as opposed to the flat namespace of NetBIOS The mechanisms that are used for resolution of DNS names are the Hosts files, DNS itself, and the DNS resolver cache 12 Module 5: Implementing Name Resolution What Is a Host Name? Slide Objective To define the host name used by Windows 2000 and common to UNIX environments ! ! Entries are stored in the Hosts File or DNS ! A host name simplifies the way a... the DNS server does not respond to any of the attempts, and no other resolution methods, such as a NetBIOS name server or Lmhosts, are configured, the process stops, and an error is reported 16 Module 5: Implementing Name Resolution # Configuring Name Resolution for Client Computers Topic Objective To explain how to configure name resolution in various Windows operating systems Lead-in ! Configuring . Module 5: Implementing Name Resolution # ## # NetBIOS Name Resolution ! What Is a NetBIOS Name? ! NetBIOS Name Cache ! Name Resolution Using Lmhosts ! Name Resolution. Implementing Name Resolution 1 Overview ! Introduction to Name Resolution ! NetBIOS Name Resolution ! Host Name Resolution ! Configuring Name Resolution