Supporting Users and Troubleshooting a Windows® XP Operating System Exam Cram™ 2 (Exam 70-27)

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Managing and Troubleshooting Network Protocols and Services

307

Configuring and Troubleshooting NetBIOS

Name-Resolution Issues

Microsoft TCP/IP supports NetBIOS over TCP/IP (NetBT) to provide

legacy name resolution for NetBIOS client and server programs in the LAN

and wide area network (WAN) environments. This includes all Windows

versions prior to Windows 2000 and all versions of Windows since Windows

2000 that are configured in a workgroup, rather than an Active Directory

domain.

When DNS name resolution fails, and Windows XP attempts NetBIOS over

TCP/IP (including WINS), name resolution uses one of five strategies.

These strategies are defined as node types:

➤ B-node—Uses broadcasts to resolve names.

➤ P-node—Uses point-to-point communications with a NetBIOS server

(such as a WINS server) to resolve names.

➤ M-node—Uses a mixture of broadcasts first (b-node) and then directed

name queries (p-node) if broadcasts fail to resolve.

➤ H-node—Uses a hybrid style with a point-to-point name query first (p-

node) and then broadcasts (b-node).

➤ Microsoft-enhanced B-node—Uses the local LMHOSTS file (this method is

unique to Microsoft) before reverting to broadcasts.

To see which node type is configured on a Windows XP Professional–based comput-

er, type ipconfig /all at the command prompt. The node type appears next to the Node

type heading.

If WINS is enabled on a Windows XP Professional–based computer, the sys-

tem uses h-node by default. Without WINS, the system uses b–node by

default. Using a name server to resolve names is generally preferable to

broadcasting for two reasons:

➤ Broadcasts are usually blocked by routers; only local network segment

NetBIOS names can be resolved.

➤ Broadcast frames are processed by all computers on a subnet and

degrade network performance.

If your network doesn’t have a WINS server or one is not available, config-

ure Windows XP Professional to use LMHOSTS for NetBIOS name reso-

lution.