Tag:data packet

  • Installation and application of Snort


    Snort experiment 1、 Experimental environment Operating system: Ubuntu 18.04, Kali Experimental tools: snort, VMware Workstation IP of unit 1: IP of unit 2: 2、 Experimental content The experimental environment needs to be built before snort configuration. The environment configuration required for the experiment is shown in the following figure: Part A Run snort […]

  • Browser three handshakes and four waves


    Three way handshaking 1. Background: TCP is located in the transport layer, and its function is to provide reliable byte stream service. In order to accurately deliver data to the destination, TCP adopts the three-time handshake strategy. 2. Principle: 1) The sender first sends a syn (synchronize) packet to the receiver. 2) After receiving, the […]

  • Favorite


    computer network explore! The mental process of a packet in the network TCP three handshakes and four wave TCP retransmission, sliding window, flow control, congestion control TCP packet capture HTTP knowledge operating system memory management Process and thread Basics file system Input / output device CPU execution CPU cache storage Zero-copy This work adoptsCC agreementThe […]

  • How to make 60 million packets and 3 million packets intersect in only 50 m memory environment


    Due to the impact of the recent epidemic situation, I believe that many small partners are busy with online office or interview recently. Here I share a topic in the online programming interview for the front-end of a large factory, How to make 60 million packets and 3 million packets intersect in only 50 m […]

  • Differences between post method and get method in http


    1. Get is harmless when the browser goes back, but post will submit the request again; 2. The URL address generated by get can be collected, but post cannot; 3. Get requests will be actively cached by the browser, while post will not be actively cached unless manually set; 4. Get request parameters will be […]

  • Principle of embedded communication protocol (SPI, UART, I2C)


    SPI How SPI works Clock Select from device Multiple slaves Mosi and miso SPI data transmission steps Advantages and disadvantages of SPI advantage shortcoming UART How UART works Start bit Data frame Parity check Stop bit UART transmission steps Advantages and disadvantages of UART advantage shortcoming I2C How does I2C work addressing Read / write […]

  • Analysis of MySQL protocol (1)


    #Preface   in the recent learning process of MySQL, one thing I always want to do is to analyze the MySQL protocol. Understanding the MySQL protocol is also the process of getting to know MySQL deeply. The content of this chapter will be divided into two chapters due to its large space. MySQL version: 8.0.20 Packet […]

  • TCP packet sticking and its solution — Based on NewLife.Net Pipeline frame length gluing method for Network Library


    catalog 1. Sticking 2. Sticking reasons 2.1. The same client sends continuously 2.2. Packet sticking caused by network congestion 2.3. The server is stuck 3. The harm of sticking package 3.1. The packet cannot be parsed correctly 3.2. Error packets are parsed by errors 3.3. Enter the dead loop 4. Logical processing method of gluing […]

  • Domain learning note 9: deploying software using group policy


    1、 Installation package deployment 1.1. Create a new folder, such as “software”, right-click it, select “share”, and click “specific user”. 2. Select “everyone” and click “add”. 3. Default “read” permission, click “share”, and finally click “finish”. 4. The deployed software extension must be in MSI format. Copy the software to be deployed to the software […]

  • PHP mysqli_ stmt_ bind_ Param mysqli function


    Definition and Usage mysqli_stmt_bind_param– bind variables to prepared statements as parameters Version support PHP4 PHP5 PHP7 I won’t support it support support grammar mysqli_stmt_bind_param ( mysqli_stmt $stmt , string $types , mixed &$var1 [, mixed &$… ] ) Pass to mysqli_ In the SQL statement of prepare(), bind variables for parameter markers. be careful: if […]

  • The use of tcpcopy tool


    Tool debugging: On line server, start tcpcopy: ./tcpcopy -x 8090- -s -c 10.5.214.x Test server, add route: route add -net netmask gw Secondary server, start listening: ./intercept -i eth0 -F ‘tcp and src port 8090′ –d Note: please refer to the tcpcopy installation tutorial for detailed commands and instructions 1 use […]

  • Use Wireshark to analyze the packet


    Note: before reading, make sure you know the basic operation of tcpdump and Wireshark~ Syn package does not return Capture location: client Phenomenon: the client sends a syn packet, and then retransmit it all the time. The time interval increases by 1 s, 2 s, 4 S, and finally disconnects. Filter command:tcp.flags.syn==1 and tcp.analysis.retransmission Reason: […]