Measure the test taker's understanding about the basic concepts of the NetBIOS protocol.

In the use of LAN, we will use the NetBIOS protocol for some application programming interfaces. Do you know this protocol? Next we will solve what is NetBIOS and NetBIOS role and application of this problem. English meaning: NetBIOS Services Protocols, Chinese meaning :( RFC-1001, 1002) basic Network input/output system protocols.

Note: This protocol was developed by IBM, the NetBIOS protocol is an application programming interface (API) that can be used by LAN programs ), provides a unified command set for the program to request low-level services to provide networks and other special functions for the LAN, the system can use WINS service, broadcast, and Lmhost files to resolve NetBIOS names to corresponding IP addresses for information communication, therefore, the NetBIOS protocol can be used within the LAN to conveniently share message communication and resources, because it occupies less system resources and delivers high transmission efficiency, it is especially suitable for a small LAN consisting of 20 to 200 computers. Therefore, almost all LAN networks work on the basis of the NetBIOS protocol ｡

Application: in Windows, NetBIOS is automatically installed after TCP/IP is installed by default. For example, in Windows 2000/XP, when "automatically obtain IP Address" is selected, the DHCP server is enabled and the NetBIOS settings are used for the server. If the static IP address is used or the DHCP server does not provide NetBIOS settings, enable NetBIOS on TCP/IP. The specific settings are as follows: First Open "Control Panel", double-click "network connection" icon to open the Local Connection Properties. Then, in the Properties window, select "Internet Protocol (TCP/IP)" on the "General" tab, and click "properties". Then, in the window that appears, click the "advanced" button; in the "Advanced TCP/IP Settings" window, select the "WINS" tab and set the corresponding NetBIOS in the "NetBIOS Settings" area ｡

NetBIOS: basic network input/output system

(NetBIOS: Network Basic Input Output System)

The NetBIOS protocol defines a software interface and a standard method for providing communication interfaces between applications and connection media. NetBIOS is a session layer protocol used in various LAN (Ethernet, Token Ring, etc) and WAN environments, such as TCP/IP, PPP, and X.25 networks ｡

NetBIOS removes the need for applications to understand Network details, including error recovery (Session mode). NetBIOS requests are provided in the form of a Network Control Block (NCB: Network Control Block, NCB contains information such as the information storage location and target name ｡

NetBIOS provides Session Layer and transport layer services in the Open System Interconnection (OSI) model, but does not support transmission of standard frames or data formats. NetBIOS Extended user interface (NetBEUI) supports standard frame formats, it provides network-layer and transport-layer service support for NetBIOS ｡

NetBIOS supports two communication modes: session or datagrams. session Mode means that two computers establish a connection for "conversation" and allow processing of a large amount of information, it also supports error monitoring and recovery. The datagram mode is intended for "connectionless" (independent message sending) operations, with little information to be sent, the error monitoring and recovery functions are provided by the application. In addition, the datagram mode also supports broadcasting information to each computer in the LAN ｡

The NetBIOS protocol name is 16 bytes long (if necessary, it is filled with fill bits), and there is almost no limit on the byte value. For small networks that do not execute routes, you can map NetBIOS names to IP addresses in three ways:

1. IP broadcast-when the target address is not in the local cache, a packet containing the NetBIOS name of the target computer is broadcast. The target computer returns its IP address ｡

2. lmhosts file-this is a file that maps IP addresses and NetBIOS computer names ｡

3. the NBNS-NetBIOS naming server maps NetBIOS names to IP addresses. This service is executed by the background program (nmbd daemon) in Linux ｡