Network O & M knowledge Summary

1. the TCP/IP protocol architecture consists of the application layer, transmission layer, Network Interconnection layer, network interface layer, and physical layer; the OSI architecture consists of application layer, presentation layer, Session Layer, transmission layer, network layer, data link layer, and physical layer.

2. Ping the ICMP protocol in the TCP/IP protocol.

3. port 443 is a Web browsing port mainly used for HTTPS services. It is another type of HTTP that provides encryption and transmission through secure ports.

4. The range of the standard port is 0 ~ 65535.

5. The command for Restarting IIS is iisreset/start or net stop IISADMIN and Net start IISADMIN.

6. The command for viewing the local file list in the FTP command is list.

6. The error http403 Indicates access is forbidden, and the error http403 indicates that access is not found.

7. Common port numbers:

Oracle 1521, 1526

DHCP 67

DNS 53

FTP 21, 20

Sqlserver 1421

Web Server 80, 8080

POP3. 110

SMTP 25

Telnet 23

8. FTP working mode and Principle

FTP is a File Transfer Protocol that supports two modes: Standard (active) and passive (PASV, passive mode ). The FTP client in standard mode sends the PORT command to the FTP server. The client in passive mode sends the PASV command to the FTP server.

In standard mode, the FTP client first establishes a connection with the TCP port 21 of the FTP server and sends commands through this channel. When the client needs to receive data, it sends the PORT command through this channel. The PORT command contains the port used by the client to receive data. When transmitting data, the server sends data through its TCP port 20. The FTP server must establish a new connection with the client to transmit data. The passive mode is similar to the standard mode when a control channel is established. When the client sends the PASV command through this channel
Server opens a random port between 1024 and 5000 and notifies the client to send data requests on this port. Then, the FTP Server transfers data through this port, at this time, the FTP server no longer needs to establish a new connection with the client.

9. Line sequence of 568a and 568b

568b orange white orange green white blue white green brown white Brown

568a green white green orange white blue white orange brown white Brown

10. Sort data access speeds (fast-slow): Hard Drive in CPU memory

11. Nic Mac is composed of six groups of hexadecimal data. The first three groups indicate vendors, which are allocated by IEEE and can be subdivided into three groups.

The serial number of a network product (such as a NIC) manufactured by the manufacturer.

12. Differences between C/S and B/S

C/s indicates the Client/Server mode. c is the client, and s is the server.

B/S is based on the Browser/Server mode, B is the browser, S is the server, C in the former is the need to develop other client programs

. The latter is implemented based on browsers, such as IE.

13. Integrated Wiring includes six subsystems

Building Group connection Subsystem

Device connection Subsystem

Trunk (vertical) subsystem

Management Subsystem

Level Subsystem

Workspace Subsystem

Including network cabling system, monitoring system, closed-circuit television system

14. The ports in the computer have a total of TCP0-65535, And the UDP0-65535 is a total of 65536*2 = 131072 ports

15. Similarities and Differences between cache and Buffer

Cache is a high-speed cache memory, which is implemented by hardware. Coordinates the processing speed between devices.

. For example, the CPU L2, L1, and memory functions.

Buffer is a buffer, which is implemented by software in Ram. Accelerate the response speed. Example

For example, Web Cache, cache in various application software, and queue.

All of them are implemented in Ram, but they are implemented in different ways.

16. MBR, Master Boot Record, and Master Boot Record. Boot OS.

17. system volume information this directory is used by the XP Auto-restore function and stores Restore Point files. Pagefile. sys is a PF, virtual memory file.

18. The basic network transmission protocols used by QQ and other instant messaging software are UDP and TCP. QQ mainly uses UDP and TCP in some cases.

19. Working Process of the computer from power-on to system startup

Power-on-[self-check]-BIOS information-video card parameters-CPU parameters-memory parameters-Hard Disk parameters-optical drive parameters-display other I/O of the Board such as PCI parameter -- (this step should be displayed if there is a RAID card) -The BIOS will update the escd and finally give the (Verifying DMI polldata ........... Update
Success)-read MBR records-call ntldr to perform a series of operations (at this time, control is transferred from BIOS to Hard Disk/OS)-read boot. INI file (displays the operating system selection menu) to enter the specified operation-and finally see the Desktop

20. When the computer is turned on, the host sends a beep and the monitor does not have any signal. This phenomenon may be caused by memory problems. Generally, the memory is loose and the dust is high. It can clean the dust and plug in the memory again. Other hardware problems can also be determined based on different tweets.

21. Steps for configuring broadband Routing

Set the dialing attribute, which is generally pppoe and the user name and password provided by the ISP.

Set valid Intranet IP addresses

We recommend that you enable the firewall function.

22. Basic vro functions: data packet forwarding.

23. Win2000 has two remote access methods: dial-up remote access and VPN (Virtual Private Network ).

24. San refers to a storage area network. It is a high-speed network or a sub-network that provides data transmission between a computer and a storage system. A San network consists of the communication structure of the network connection, the management layer of the Organization and connection, the storage components, and the computer system, so as to ensure the security and strength of data transmission.