It is popular that the network protocol is communication between the network, the bridge between the communication, and only the same network protocol computer can communicate and communicate with information. This is like communication between people to communicate with people, only use the same language to communicate normally, smoothly. From a professional perspective, the network protocol is the agreement that the computer must comply with the communication in the network, that is, the communication protocol. Mainly, the rate, transmission code, code structure, transmission control step, error control, etc. of information transmission, and standards. We organize these articles to form a complete set of hopes to help beginners.
Protocol x file (1)
First, what is the network protocol?
It is popular that the network protocol is communication between the network, the bridge between the communication, and only the same network protocol computer can communicate and communicate with information. This is like communication between people to communicate with people, only use the same language to communicate normally, smoothly. From a professional perspective, the network protocol is the agreement that the computer must comply with the communication in the network, that is, the communication protocol. Mainly, the rate, transmission code, code structure, transmission control step, error control, etc. of information transmission, and standards.
Second, the choice of network protocol
In the face of numerous network protocols, we may have no choice. However, if you know the main purpose of the network protocol, you can have targeted choices. For example, the TCP / IP protocol we are familiar with is the standard protocol of the Internet, and you must use the protocol through the LAN access Internet. The NetBeui protocol is mainly used in a local area network of 1 to 200 computers, mainly used in MS-DOS, Windows environments. Other network protocols, we will introduce one by one below.
Third, the common network protocol installation
In Windows 98/2000 / XP / Server 2003, the method of installing the network protocol is roughly the same. The following is to install the NetBeui protocol as an example, which is described in Windows 98 and Windows 2000 / XP, respectively.
1. WINDOWS 98
First open the Control Panel, double-click Network, click the Add button in the open window; then select "Protocol" in the Select Network Component type, click the Add button; in the open window You can choose to install the network communication protocols of each manufacturer, such as
Microsoft's NetBeui protocol (Figure 1), and then click the "OK" button to install the protocol. After the installation is complete, you can see the protocol in the component of the network window. After restarting, the setting takes effect.
figure 1
2. Windows 2000 / XP To install the NetBeui protocol in Windows 2000 / XP is more troublesome, first, you need to copy the "nbf.sys" file in the "ValueAdd / MSFT / NET / NETBEUI" directory in the Windows XP installation CD to% systemRoot%. In the / system32 / drivers / directory, you also copy the "Netnbf.inf" file to the% systemroot% / inf / directory. Then, open the Control Panel, double-click Network Connections; then right-click "Local Connection", select Properties to open the local connection properties window; click the "Install" button (as shown in Figure 2), in the Network Component Type Window Select the Protocol, click Add. Select "NetBeui Protocol" in the following window, click the "OK" button to install the protocol.
figure 2
Tip: If you don't have the protocol you want to install in the pop-up window, you can click the "Select Network Protocol" window to select the "From the Disk Install" button to select it from another location.
Protocol X Archives (2) Friends on the Internet should be very familiar with what is IP address, whether logging in to the Internet setting, or a local area network setting, or more or less to contact IP addresses. In fact, the IP itself is a network protocol. At present, the IP protocol we use is strictly called IPv4. Here we will explain the contents of IP, IPv6, TCP, and TCP / IP protocols. IP protocol Description: Full term Internet protocol, mainly for IP addressing, routing, and IP packet segmentation and assembly. Usually what we said can be understood to comply with the address of the IP protocol. At present, our common IP protocol is the fourth version of the IP protocol, ie IPv4, is the most basic protocol in the Internet, defined in RFC 791 in 1981. Application: IPv4 uses 32-bit addresses, usually used in four decimal numbers separated by dots, such as 192.168.0.1. Currently, IPv4 supports up to 4294967296 (2 32 times) addresses to the Internet. With the rapid development of the Internet, the demand for IP addresses is getting bigger and bigger, and there is a crisis that is used in the next few years. IPv6 protocol Description: The full name Internet Protocol Version 6, the IP protocol 6.0 version, is often also referred to as the next generation Internet protocol, IPv6 is a new IP protocol for replacing the current IPv4 protocol for the Internet Engineering Task Group (ITF) development design . IPv6 and IPv4 effects are roughly the same. The purpose of development is mainly to alleviate the pressure of IPv4 address space, and there is also some problems of the IPv4 protocol, including end-to-end IP connection, quality of service (QoS), security, scalability, and ie Plug and play and so on.
Application: 1. Install IPv6 IPv6 use 128-bit addresses, which can be provided with a 128th address of 2. To install IPv6 in Windows XP, you can "start → run" in turn, enter "CMD" Enter the "Command Prompt" window; then type: IPv6 install (as shown above), you can install IPv6 after entering! 2. Configuring IPv6 is also in the "Command Prompt" window, type: IPv6 IF, get the interface index after entering the bus, add the received address by this interface; type: IPv6 adu [interfaceIndex] / [address], where InterfaceIndex indicates the interface number of the interface, and address represents an IPv6 address. In addition, you can also use the ping6 command to perform IPv6 configuration and connection testing, specific command usage, you can add the associated help file after the command. TCP Protocol Description: Full title Transmission Control Protocol, which is primarily used to create a virtual connection between hosts to achieve high reliability packet exchange. Application: The IP protocol we introduced above can split and assemble the IP packets, but through the IP protocol, it is not clearly understood whether the packet is successfully sent to the target computer. The TCP protocol is different. After this protocol transmission mode is successfully sent to the target computer, TCP will request a confirmation; if it does not receive a confirmation within a time limit, then TCP will resend the packet . In addition, during transmission, the TCP can also be responsible for recovery if the data packets are received, and the TCP is received. TCP / IP protocol Description: TCP / IP protocol is actually a combination of protocols such as TCP and IP, the transfer control protocol / Internet protocol, which is very extensive, mainly for different hardware and different operations installed. Reliable network communication between the system's computer. Among them, the TCP protocol ensures the reliability of packet transmission; the IP protocol ensures that the packet can be passed to the target computer. In addition to TCP, IP protocol, TCP / IP protocol combinations include protocols such as FTP, Telnet, SMTP. Application: Currently, almost all network communication devices and operating systems support TCP / IP protocols.
Protocol X Archive (3) In the previous period, we introduced everyone familiar with TCP / IP protocol and the contents of IP, IPv6, TCP protocol. In this issue, the IPX / SPX protocol associated with the NetWare server, the game, and the IPX routing protocol, the content of the SPX protocol. IPX protocol Description: Full term Internetwork packet Exchange (Internet Packet Exchange), IPX protocol is the best network protocol comes with Novell NetWare, mainly used to control the addressing and routing of packets between local area or local area networks, only responsible for data The transfer in the local area network does not guarantee the integrity of the message, nor does it provide error correction services. Application: When transmitting a packet in a local area network, if the receiving node is transmitted directly to the ID of the node through the IPX protocol; if the receiving node is not in the same network segment, then the IPX protocol can be The packet is given to the NetWare server and continue to transfer. During use, network administrators can use the corresponding IPX routing commands, such as "Routing IPX Add / Set StaticRoute" means adding or configuring static IPX routing in the IPX routing table, "Routing IPX Set Global" means configuring global IPX routing. Set. SPX Protocol Description: Full name Sequences Packet Exchange (order), SPX protocol is based on Xerox Xerox SPP (Sequence Packet Protocol, the Order Package Protocol) protocol, which is also a network protocol for local area networks developed by Novell. In the local area network, the SPX protocol is mainly responsible for error-free processing of the entire transmission of data, ie error correction. Application: The SPX protocol is generally combined with the IPX protocol described above into the IPX / SPX protocol, which is used for NetWare network environments and networking games. IPX / SPX protocol
Description: The IPX / SPX protocol is a combination of IPX and SPX protocol. It is a communication protocol developed by Novell to adapt to the development of the network. It has strong adaptation, easy to install, and also has routing functions. You can implement multiple network segments. Communication. Among them, the IPX protocol is responsible for the transfer of packets; SPX is responsible for packet transmission integrity. In Microsoft's NT operating system, both NWLINK IPX / SPX compatible protocols and NWLink NetBio's two IPX / SPX compatibility protocols, the NWLINK protocol, which inherits the advantages of the IPX / SPX protocol, and adapt to Windows network environments . Application: IPX / SPX protocol can generally be applied to large networks (such as Novell) and local area network gaming environments (such as counter-terrorism elites, StarCraft). However, if not in the Novell network environment, IPX / SPX protocols generally do not use IPX / SPX compatible protocol, especially in Windows 9x / 2000 peers. The method of installing the IPX / SPX compatibility protocol in Windows is approximately as follows: For example, in Windows XP, first open the Network Connection window, right-click "Local Connection", select "Properties" to open the local connection properties window; then click " Installing the button, select the Protocol component, click the "Add" button; select "NWLINK IPX / SPX / NetBIOS Compatible Transport Protocol" in the open window, finally, click the "OK" button to do installation. After installation, you can use it without any settings. Protocol x file (four)
NetBIOS protocol
Description: The full name NetWork Basic Input / Output System (Network Basic Input / Output System), the protocol is
IBM has developed, mainly used in small local area networks for dozens of computers. The NetBIOS protocol is an application programming interface (API) that can be used on the LAN, providing the program with a unified command set for low-level services, and the role is to provide networks and other special features to the LAN, almost all local area networks. It works on the basis of the NetBIOS protocol.
Application: In the Windows operating system, the NetBIOS is automatically installed by default after installing the TCP / IP protocol. For example, in Windows 2000 / XP, the DHCP server is enabled after selecting "Auto Get IP", using NetBIOS settings from that server; if NetBIOS settings are not available using a static IP address or DHCP server, NetBIOS on TCP / IP is enabled. The specific setting method is as follows: First open the Control Panel, double-click the Network Connection icon to open the local connection properties. Next, select Internet Protocol (TCP / IP "in the" General "tab of the attribute window, click the Properties button. Then in the open window, click the Advanced button; select the "WINS" tab in the Advanced TCP / IP Settings window, and you can set the corresponding NetBIOS in the NetBIOS Settings area (Figure 1).
NetBeui protocol
Description: The full name NetBIOS Extend User Interface (NetBIOS user expansion interface) is also
IBM proposed in a small LAN in 20 to 200 computers in 1985, such as early DOS, LAN Manager, Windows 3.x, and so on. The NetBeui protocol can be regarded as an extension of the NetBIOS protocol, improved version, which has a small size, high efficiency and fast speed. NetBeui can be seen as a transport protocol, and NetBIOS is just a set of commands to use the network. Application: The NetBeui protocol is mainly used in the local LAN, which is generally unable to communicate with a computer of other networks, different from the TCP / IP, IPX / SPX protocol described earlier. In Windows, the method to install the NetBeui protocol is not the same. For example, in Windows 98 / ME, just double click on "Network" in the Control Panel, "Add" protocol in the open attribute window, select
Microsoft's NetBeui protocol is installed. In Windows XP, copy the "nbf.sys" file in the "ValueAdd / MSFT / Net / NetBeui" directory in the disc installation CD to the% SystemRoot% / System32 / DRIVERS / directory, and then "Netnbf.inf" file Copy to the% SystemRoot% / INF / directory; this can see "NetBeui Protocol" in the Select window when installing the Protocol, (Figure 2).
Figure 1 Enable NetBIOS protocol
Figure 2 Install the NetBeui protocol
Protocol x file (5)
BOOTP protocol
Description: The full name Bootstrap Protocol (Subload Agreement) is a protocol based on TCP / IP protocol, which allows diskless station to get IP addresses from a central server, assigning dynamic IP addresses in the LAN, Do not need each user to set the static IP address. When using the BOOTP protocol, generally include both Bootstrap Protocol Server and Bootstrap Protocol Client.
Application: This protocol is mainly used in a local area network with diskless workstations. The client gets the IP address is as follows: First, start the client by the Bootp start code, this time the client has no IP address, use the broadcast form 0.0 .0.0 issues an IP address query request to the network. Next, the server running the Bootp protocol receives this request, which will find the client according to the MAC address provided in the request, and send a FOUND frame containing the IP address, server IP address, gateway, etc.. Finally, the client will download the mirror file based on the Found frame to download the mirror file through the dedicated TFTP server, and simulate into disk launch.
TFTP protocol
Note: The full name Trivial File Transfer Protocol (simple file transfer protocol or fragile file transfer protocol), the role of the TFTP protocol is roughly the same as the FTP we often use, and it is used for file transmission, which can realize two computers in the network. File upload and download. You can see the TFTP protocol as a simplified version of the FTP protocol. The difference is mainly: 1. The TFTP protocol does not require the permission of the client, and FTP needs to perform client authentication; Second, TFTP protocol is generally used for local area network and remote Unix computer The common FTP protocol is used in the Internet.
Application: Windows 2000 / XP / Server 2003 built-in TFTP commands, we can type the TFTP command in the "Command Prompt" window to transfer local computer files to the remote computer. For example, to transfer an abc.txt file on the local computer to abc1.txt on the remote smile computer, we can type: TFTP smile put abc.txt abc1.txt. Specific command usage, you can type in the "Command Prompt" window: TFTP /? Can see the corresponding prompt information. DHCP protocol
Description: The full name Dynamic Host Configuration Protocol automatically assigns an IP address for each computer in the LAN, and completes TCP / IP protocol configuration of each computer, including IP addresses, subnet masks Codes, gateways, and DNS servers, etc. In this way, in the LAN, in particular a large local area network, the administrator does not have to manually configure the TCP / IP protocol for each computer, and the IP address repeated problem is avoided.
Application: To enable the DHCP protocol in Windows, just set the IP address to "automatically get the IP address". The specific method is as follows: Take Windows XP as an example, open the Local Connection property, double-click the Internet Protocol (TCP / IP) to open the property window. Then, select "Auto Get IP Address" in the General tab, click "Advanced" in the lower right corner. Below the "IP Settings" tab of the window, you can see "DHCP Enable" (as shown above).
Protocol X Archive (6) We know the Bootp protocol for automatically obtain IP addresses for diskless workstations, and TFTP protocols for simple file transfer and DHCP protocols for automatically assign IP addresses. The Internet Control Message Protocol (ICMP), Internet Group Management Protocol (IGMP), and Route Information Protocol (RIP) will be described below. ICMP protocol Description: Full term Internet control message protocol (Internet Control Message Protocol), a sub-protocol in the TCP / IP protocol concentration, which belongs to the network layer protocol, mainly used to transfer control information between the host and the router, including report errors , Exchange restricted control and status information, etc. When you encounter IP data that cannot be accessed, the IP router cannot send ICMP messages when the current transfer rate is forwarded. We can send an ICMP response request message through the ping command and record the received ICMP response message, and provide a reference basis for the fault of the network or host by these messages. Application: To use this protocol, we can make the corresponding ICMP settings, such as in Windows XP, first open "Network Connections", right-click Network Connections, select "Properties" to open the Properties window. Next, select the Advanced tab, click the "Settings" button in the lower right corner. Then, select the "ICMP" tab in the Advanced Settings window (as shown below), in which the corresponding settings can be performed, including the returns request, and the like. IGMP Protocol Description: Full term Internet Group Management Protocol (Internet Group Management Protocol), which is run between the host and the multicast router directly connected to the host, is an IP host to report the identity of the multicast group member identity. Through the IGMP protocol, on the one hand, the local router can be notified to the local router to add and receive information about a particular multicast group; on the other hand, the router periodically queries if a known group of a known group in the local area through the IGMP protocol. Active status. Application: The main role of the IGMP protocol is to solve the problem of occupying bandwidth when broadcasting broadcasts. In the network, when broadcasting information is sent to all clients, IGMP switches will be sent to all clients without filtration. However, this information only needs to be transmitted to a part of the client through multicast. RIP protocol Description: Full title Routing Information Protocol (Route Information Protocol), the protocol is the launch of Xerox Company, mainly for small-scale network environments. The RIP protocol is mainly used in the transmission of routing information in an AS (autonomous system). Send a routing information update every 30 seconds. The RIP protocol provides a hop count as a scale to measure the routing distance, and the jump count is a package to reach the target. The number of routers that must be passed, the number of hops supported by RIP is 15. Application: In Windows, we can listen to the RIP message by enabling the "RIP listening" feature so that the computer can understand other routes and then add their IP addresses to the routing table. Take Windows XP as an example, the specific enable "RIP listening" function method is as follows: First, open "Control Panel", double-click Add or Remove Programs. Next, click Add or Remove Windows Components, click Network Services, and then click Details. Check the "RIP Listener" check box and click the "OK" button to install the component.
Protocol X Archives (7) We already know the protocol (ICMP), Internet Group Management Protocol (IGMP), and Routing Information Protocol (RIP) for delivering Internet Control Messages. The network protocol related to file delivery / mail will now be introduced. FTP protocol Description: Full-name File Transfer Protocol, this is one of the very familiar network protocols and the most file transfer protocol used in the Internet. Mainly used to implement files and downloads between the two computers, one of which is the client side of FTP, and another as a server side of FTP. Uploaded through the FTP protocol, download almost all file types, such as TXT, EXE, DOC, MP3, ZIP, RAR, etc. Application: In practical applications, FTP can not only be used as the main format of the network file download, but also as a separate command. For example, when we are under MP3, you often encounter ftp://www.xxx.com/1.mp3, where ftp: // represents file transfer format, www.xxx.com represents a remote computer domain name, 1.MP3 is Download the file. In addition, the FTP command is also integrated in Windows. For example, type "ftp www.xxx.com" in Windows XP "Command Prompt", you can open www.xxx.com remote computers, the specific command parameters can be typed " ftp /? ". Telnet protocol Description: The full name remote login protocol, which is also a commonly used simulation network protocol on the Internet, while Telnet is also a commonly used program from a remote location. You can use your computer as a terminal of a remote computer through a Telnet protocol, log in to the remote Telnet computer through the Telnet program, usually use the authorized username and password to log in. After logging in, use the local computer using the remote computer's hard drive, running applications, etc. Application: In Windows, we can use the telnet command to log in remotely, such as type "Telnet www.xxx.com" can connect to www.xxx.com remote computer, and can also specify the login user name, terminal type by setting parameters. And port numbers, etc., the specific command parameters can type "Telnet /?" View (as shown below).
NEWS protocol Description: The full name network newsgroup protocol, through the agreement to access a variety of newsgroups in the Internet, get the information, resources you need from the newsgroup, including political, economic, cultural, humanities, geography, technology Wait, you can also post some information in the newsgroup. Application: The usage format of the protocol is: news: newsgroup, newsgroup represents the network newsgroup address, such as the Microsoft Chinese News Group server address is: msnews.microsoft.com, type: news: msnews.microsoft. COM, you can open the OE to access the newsgroup after entering you. MAILTO protocol Description: Represents an email protocol, you can create a hyperlink to the email address, which can be sent in the Internet with this link. Application: For example, insert a paragraph A href = "way: abc@xxx.com" in the web code, click the hyperlink to open the OE and other mail client programs, enter the corresponding content, you can go to abc@xxx.com send email. In addition, in the address bar of the IE browser: abc@xxx.com, which can also achieve such an effect after entering the bus. File Protocol Description: Represents a local file transfer protocol, the File protocol is mainly used to access files in the local computer, just like opening the file in the Windows Explorer. Application: To use the File protocol, the basic format is as follows: file: /// file path, such as the 1.swf file in the Flash folder, you can type: file in the resource manager or IE address bar : /// f: /flash/1.swf and enter. Protocol X Archive (8) When the Dial-Up and ADSL Broadband Internet access, we often use protocols such as SLIP, PPP, and PPPoE to create dial-up connections. In this issue, we will introduce SLIP, PPP, PPPoE, L2TP related to network transfer. PPTP protocol.
SLIP protocol
Note: The full name Serial Line Internet Protocol, which is an old industrial standard for Windows remote access, mainly in the UNIX remote access server. Because the SLIP protocol is a low-speed serial line, it can be used for a private line, and can also be used for dialing lines, and the MODEM's transmission rate is at 1200 bps to 19200 bps.
Application: Set the SLIP protocol in Windows, such as in Windows 98, assume that "Dial-up Connection" has been created, right-click the connection, select Properties. Next, in the open attribute window, select the Server Type tab, select "SLIP: UNIX Connection" in Dial-Dial Network Server Type. Finally, click the "OK" button.
PPP protocol
Description: The full name Point To Point Protocol is a sub-protocol in the TCP / IP Network Protocol collection, mainly used to create a telephone line and ISDN dial-up access ISP, with multiple authentication methods, data compression and Encryption and notify the IP address. The PPP protocol is an alternative protocol for the SLIP protocol, which is not very different.
Application: Suppose it is also in Windows 98, and has created a "dial-up connection". Then you can set the PPP protocol by the following method: First, open the Dial-Dial Connection property, choose the Server Type tab; then select the default "PPP: Internet, Windows NT Server, Windows 98" (Figure 1) ), Can set other function options in the advanced option; Finally, click the "OK" button. PPPoe protocol
Note: The full name Point to Point Protocol over Ethernet (Point-to-point protocol on Ethernet), simply, the agreement after the Ethernet and PPP protocols are widely used in the ADSL access method. With PPPoE technology and broadband modems (such as ADSL MODEM), we can implement personal authentication access for high-speed broadband networks, create virtual dial-up connections for each user, so you can connect to the Internet at high speed.
Application: In Windows XP, the virtual dial tool with the PPPoE protocol, the specific creation method is as follows: First, open "network connection"; then click "Create a new connection" under the "network task" on the left side of the window. Open New Connection Wizard, click Next; select "Connect to the Internet" in the Network Connection Type, click Next; and select "Manually Set my connection" in the window, click "Next"; Select "Use to connect to the broadband connection to the username and password" in the Internet Connection window "(Figure 2), click Next; enter the ISP name, such as" ADSL ", click" next step "; Enter the username, password, confirm password, click Next, click" Finish ".
PPTP protocol
Description: The full name Point-To-Point Tunneling Protocol (point-to-point tunnel protocol), the protocol is a new enhanced security protocol developed on the basis of the PPP protocol, supports multi-protocol virtual private network (VPN), which can pass password identity Verification Protocol (PAP), Extensible Authentication Protocol (EAP) and other methods to enhance security. The remote user can access the enterprise network securely by direct connection to Internet or other networks by dialing the ISP.
Application: You can use the PPTP protocol when using the VPN, you can also use the L2TP protocol, the specific setting method is as follows: For example, in Windows XP, first right click on a VPN connection in the Network Connection window, select "Properties" . Next, select the Network tab in the open attribute window. Then select "PPTP VPN" in "VPN Type" (Figure 3), click the "OK" button.
L2TP protocol
Description: The full name Layer 2 Tunneline Protocol (Layer 2 Tunnel Agreement), which is an industrial standard Internet tunnel protocol, which is roughly related to the PPTP protocol, such as encryption of network data streams. However, there are differences, such as PPTP requires networks for IP networks, and L2TP requires point-to-point connections for packets; PPTP uses a single tunnel, L2TP uses multi-tunnel; L2TP provides packet header compression, tunnel verification, and PPTP does not support. Application: Set the L2TP connection in the VPN connection, the method is set to the PPTP VPN, which is also set to "L2TP IPSec VPN" in the Network tab of the VPN Connection Properties window.
Figure 1 Set PPP protocol
Figure 2 Add a PPPoE protocol
Figure 3 Select PPTP Security Protocol
Protocol X Archives (Nine) In this article, we will introduce DNS, ARP, RARP, and MAC protocols. DNS protocol Description: Full title Domain Name Server, simply, the protocol is primarily converted to the domain name into a network that can be identified, such as converting www.cce.com to 221.122.32.15, domain name and The IP address is one or one. Because when accessing the website, it is ultimately converted into an IP address for access. If you directly set the DNS server, you can improve the access speed of the network, and the correctness of access can be guaranteed. Application: Use the DNS protocol in Windows, just set the corresponding DNS server address. The specific method is set to the IP address: For example, in Windows XP, first, open the "Local Connection" property window, double-click "Internet Protocol (TCP / IP)" in the General tab; then in the open properties window , Select "Use the IP Address" to set the IP address, subnet mask, and default gateway. Check "Use the DNS server address below" (as shown below), enter the corresponding DNS server address in the preferred DNS server and alternate DNS server. Finally, click the "OK" button continuously.
ARP protocol Description: Full name Address Resolution Protocol .0.1 NIC MAC address is 00-03-0F-FD-1D-2B. The entire conversion process is a host to send a broadcast packet containing IP address information first to the target host, that is, an ARP request, and then the target host sends an IP address and MAC address packet to the host, two hosts passing through the MAC address. Realize data transmission. Application: There is a special ARP cache in a computer installed an Ethernet network adapter, contains one or more tables for saving the IP address and the resolved MAC address. To view or modify information in the ARP cache in Windows, you can use the ARP command to complete, for example, type "arp -a" or "arp -g" in the Windows XP command prompt window to view the contents of the ARP cache; Type "ARP -D ipaddress" means deleting the specified IP address item (iPadDress represents the IP address). Other usages of the ARP command can type "ARP /?" check. RARP Protocol Description: Full term REVERSE ADDRESS RESOLUTION protocol (reverse address resolution protocol) The broadcast request for the Self IP address is issued via the RARP protocol, and then the RARP server is responsible for answering. Application: RARP protocol is widely used to obtain IP addresses of the diskless workstation. MAC protocol Description: Full-name Media Access Control (Media Access Control Sublayer), which is located in the lower half of the data link layer in the OSI seven-layer protocol, which is mainly responsible for controlling the physical media to connect the physical layer. When sending data, the MAC protocol can determine whether the data can be transmitted in advance. If it can be sent to add some control information, it will eventually send data and control information to the physical layer in a predetermined format; when receiving data, Mac The protocol first judges the input information and whether a transmission error occurs. If there is no error, the control information is removed to the LLC layer. Application: Whether in the traditional Wired LAN (LAN) or in the current popular WLAN (WLAN), the MAC protocol is widely used. In the traditional local area network, the physical layer of various transmission media corresponds to the corresponding MAC layer, and the network currently used is the MAC layer standard of IEEE 802.3, using CSMA / CD access control mode; and in the wireless LAN, MAC The corresponding standard is IEEE 802.11, and its working mode uses DCF (Distributed Control) and PCF (Center Control). Protocol x file (10)
Wireless LAN (WLAN) is used as the largest hotspot in 2004, which has been used more and more people. Different Wired Bureau Domain Domain Domain Us, the protocol used in Wireless LANs mainly includes 802.11b, 802.11a, 802.11g, and WEP security protocols. 802.11b Description: 802.11b The protocol is approved by IEEE (Electrical Electronics Engineer Society) in September 1999. The wireless network of the protocol at 2.4GHz frequency, the maximum transmission rate can reach 11Mbps, which can be implemented in 1Mbps, Automatic switching between 2Mbps, 5.5Mbps, and 11Mbps; DSSS (direct sequence exhibition technology), theoretically, the maximum transmission distance in the room can reach 100 meters, and the outdoor can reach 300 meters. Currently, 802.11b is also called Wi-Fi. Application: At present, the 802.11b agreement has been widely used in the field of wireless local area network, which is widely used in the field of wireless local area network protocols. In the wireless LAN, the 802.11b protocol mainly supports the two working modes of AD HOC (point-to-point) and Infrastructure (basic structure), and the former can implement wireless connections between wireless NICs, which can make all wireless network cards with wireless AP Wireless connection with it. 802.11a Agreement Description: 802.11a The agreement is also completed in 1999. It is mainly working at a frequency of 5 GHz, and the data transmission rate can reach 54Mbps, and the transmission distance is between 10 meters to 100 meters; use OFDM (positive The cross-frequency division multiplexing) modulation technology can support voice, data, and image transmission, but is not compatible with the 802.11b protocol. Application: 802.11a The protocol is fast, but also because 5GHz operating frequency is used, the interference is relatively small, and it is also applied to Wireless LAN. But because the price is expensive, it is not compatible, so it is not popular in the market. 802.11g Standby: 802.11g The agreement was officially launched in June 2003. It is an improved agreement based on the 802.11b protocol, support 2.4GHz operating frequency and DSSS technology, and combines the characteristics of the 802.11a protocol and OFDM. technology. Such an 802.11g protocol can achieve a 11 Mbps transfer rate, maintaining a compatibility of 802.11b, but also achieving a 54 Mbps high transmission rate. Application: With people's requirements for wireless local area network data transmission, 802.11g protocols have also slowly popularized in Wireless LANs, and the products of the 802.11b protocol occupy most of the wireless LAN market. Moreover, some of the reinforced 802.11g products have entered the wireless 100 megadownload. WEP protocol Description: Full-name Wired Equivalent Protocol (wired equivalent protocol) is a security protocol launched to ensure the security of 802.11b protocol data transmission, which can be encrypted by transmitted data, which ensures data in Wireless LAN The security of the transmission. At present, in the market, the general wireless network product supports 64/128 or even 256 WEP encryption, and the future will slowly popularize the WEP's improved version --WEP2.
