uhf waves

removal of TCP connections requires sending four packets, so called four waves (Four-way handshake). Either the client or the server can initiate a wave gesture, and in socket programming, any party performs a close () operation to generate a wave. 　 See Wireshark Grab bag, the measured capture results are not strictly according to the wave timing. I reckon the time interval is too short to cause. 1. Establish Connection Agreement (three handshake)(

of initiating active shutdown, the specific process such as:Figure 4 waving at the same timeProcess and status in the already very clear, here no longer repeat, you can refer to the previous four waves wave resolution steps.Iv. notesOn the three-time handshake and four waves usually have a typical face test, which is presented for the needs of the XDJM for reference:(1) What is the three-time handshake or

the system and delete all detected magic waves (Worm. mocbot. a, also known as WORM_IRCBOT.JL), magic wave Variant B (Worm. mocbot. b, also known as WORM_IRCBOT.JK. Trend Micro users must download the latest virus pattern file before scanning the system. Other Internet users can use Housecall, which is a free online virus scan by Trend Micro. Apply patches this virus uses known vulnerabilities to download and install patches. Avoid using affected pro

= 100 Step 2 B confirm that SYN is received, that is, seq = 100 packets And want to accept the next packet ACK = 100 + 1 that is 101 packets At the same time, B will also tell a to randomly generate the initial aeq, such as seq = 300. Send seq = 300, ACK = 101 packets Step 3 A receives ACK = 101 from B, and sends its seq = 100 + 1 to B. At the same time, B is expected to continue to send data packets, then ACK = 300 + 1 In step 2, Ack confirmation and SEQ packet transmission are synchronized.

process given above is called a three-time handshake (three-way handshake).Why does a have to send a confirmation? This is primarily to prevent a failed connection request message from suddenly being sent to B, resulting in an error. Now look at the TCP four waves (release the connection)Now both A and B are in the established state. A's application process first sends a connection release segment to its TCP and stops sending the data, actively shutt

Inspur summit is one of the two good books I expected this year (the other is known as hacker and painter). In fact, I have read many books about the history of the information industry or the legend of Silicon Valley over the past 10 years. I have also read foreign works and domestic edited works, most of the things are similar to those made up of different things. Almost no instinct is as shocking as the top of the waves. A grand vision and a uniqu

Python implements the method of crawling novels by waves, This article provides an example of how Python crawls a stream-by-wave novel. Share it with you for your reference. The specific analysis is as follows: I like to read novels on the Internet. I have been using a novel download reader. I can automatically download the novels I want to read from the Internet to my local location, which is more convenient. Inspired by the Python crawler, I suddenl

first ensure that all data transmitted to a has been transferred before the disconnection, and once the data is transmitted,The Fin field of the reply message is set to 1, and a random seq sequence number is generated. (Fin=1,ack=x+1,seq=z,z generated randomly by the server)4. When the client receives a TCP disconnect request from the server, it responds to the service-side disconnect request, including a randomly generated SEQ field and an ACK field.The ACK field adds 1 to the server-side TCP

your clothes, as shown in the following figure: New layer, filled with black, layer mode: Multiply, opaque 20%, as shown below: Find a blue sky and white clouds of material, to extract the cloud, a lot of methods, not introduced. Change the mode, lightness, use a black brush to remove unwanted clouds. The following figure: Find a source of the waves and extract the waves. Use a black brush to

three handshake familiar, four times wave estimated that the so-called Four waves (Four-way Wavehand) that terminates the TCP connection, When disconnecting a TCP connection, the client and server are required to send a total of 4 packets to confirm the disconnection of the connection. In socket programming, this process is triggered by executing close on either side of the client or service side, as shown in the entire process:Figure 3 TCP Four

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re-sent. The time required in the TIME_WAIT state is dependent on the implementation method. Typical values are 30 seconds, 1 minutes, and 2 minutes. The connection is formally closed after waiting, and all resources (including the port number) are released."Question 1" Why is the handshake three times when it is connected and four times when it is closed?A: The syn+ack message can be sent directly after the server receives the SYN connection request message from the client side. Where the ACK

ACK message, and allocates resources for this connection. An ACK message is also sent to the server segment after the client receives an ACK message, and the resource is allocated so that the TCP connection is established.The process of disconnecting the connectionThe disconnect end can be either the client side or the server side. Assuming the client side initiates an interrupt connection request, the FIN message is sent first. After the server has received the FIN message, but if there is no

disconnect end can be either the client side or the server side. The assumes the client side initiates an interrupt connection request and sends the FIN message first. After the server has received the FIN message, but if there is no data sent to complete, you do not need to close the socket, you can continue to send data. So to stop. At this point the client enters the fin_wait state and continues to wait for Fin messages on the server side. . After the client receives the fin message, it is

interrupt request 1, the client sends a FIN message to the server and informs the server that I want to interrupt the connection. At this point the state of the client is Fin_wart_12, after the server receives fin, if no data is sent, then send an ACK to the client. On my behalf I received your request for interruption, but I still have data to send to you. At this point the client status is Fin_wait_2. The state of the server is CLOSE_WAIT3, when the server has no data to send to the client, t

re-sent. The time required in the TIME_WAIT state is dependent on the implementation method. Typical values are 30 seconds, 1 minutes, and 2 minutes. The connection is formally closed after waiting, and all resources (including the port number) are released."Question 1" Why is the handshake three times when it is connected and four times when it is closed?A: The syn+ack message can be sent directly after the server receives the SYN connection request message from the client side. Where the ACK

messages to each other, that is, close the connection. So what you need to accomplish in the close_wait state is waiting for you to close the connection. (Passive side)Last_ack: This state is still relatively easy to understand, it is the passive close side after sending fin messages, and finally wait for each other's ACK message. When an ACK message is received, it is also possible to enter the closed available state. (Passive side)CLOSED: Indicates a connection interruption.# Why do I need to

What is TCP?Specifically about what TCP is, I'm not going to say it in detail; When you see this article, I think you know the concept of TCP, and want to get a deeper understanding of TCP's work, we will continue. It's just a super-messy protocol, and it's the foundation of the Internet and the basic skills that every programmer must have. First look at the OSI seven-layer model:http://www.0xffffff.org/?p=1131Http://www.nowcoder.com/discuss/1922?type=order=0pos=19page=1http://blog.csdn.net/xsf5

be re-sent. The time required in the TIME_WAIT state is dependent on the implementation method. Typical values are 30 seconds, 1 minutes, and 2 minutes. The connection is formally closed after waiting, and all resources (including the port number) are released."Question 1" Why is the handshake three times when it is connected and four times when it is closed?A: The syn+ack message can be sent directly after the server receives the SYN connection request message from the client side. Where the A

recommended that you read the two books, "heterogeneous" and "the top of the waves. Inspur Summit summarizes the growth and failure of big IT companies on the same stage as Apple in 20 or 30 years, helping them better understand apple and Steve Jobs. "Heterogeneous" puts a wider and deeper field of view, explores the common characteristics of masters in various fields, and finds that masters require at least 10 thousand hours of deep training, in add