wireshark tcp errors

Use python to implement wireshark's follow tcp stream function In short, wireshark has a follow tcp stream function, which is very convenient. The disadvantage is that the extracted stream data does not have any timestamp or other information, and it is insufficient to analyze the data delay and packet loss problems. Here, python is used to implement a simple fol

be seen from the info column of the packet list panel and the TCP packet header of packet details. After the first three packets, you can see that the value is reduced immediately, as shown in: The window size is changed from 8760 bytes of the first packet to 5840 bytes of the second packet to 2920 bytes of the third packet. The decrease in the window size is a typical sign of host latency. Note in the time bar that this process happened very quickl

Last week in the company encountered a problem, with Wireshark capture system to the network management reported data found that there are many messages are identified as "TCP segment of a reassembled PDU", and each piece of the message is 180Byte, at that time to see such an identity, Think is the IP message Shard, thought the System interface MTU value for the setting is small, through the command query f

Tags: Internet applications, IP protocol, computer internet Wireshark packet capture illustration TCP three-way handshake/four waves details 1. The link layer, also known as the data link layer or network interface layer, usually includes the device driver in the operating system and the network interface card corresponding to the computer. They work together with the physical interface details of the cabl

The structure of the Ethernet message is as follows:wherein, the Ethernet frame header:Bytes:mac Destination Address 48bit (6B), Mac Source address 48bit (6B), type domain 2B, altogether 14B.IP header:TCP Header:Http://blog.163.com/[email protected]/blog/static/618945432011101110497885/Http://www.cnblogs.com/zhuzhu2016/p/5797534.htmlThat is, the header of the message has a total of 54 bytes. The following is a simple HTTP request to view the actual status of Ethernet messages, as follows:The con

it is handed over to the application process. The latter method will improve the system efficiency. For example, the sender continuously sends a TCP datagram of 100 bytes in each packet, whose serial numbers are 1,101,201 ,..., 701. If the other seven datagram packets are received, but the 201 datagram is not received, the receiving end should confirm the two datagram packets 1 and 101 and submit the data to the relevant application process, the five

len) 999 c--"sseq=999 ack=2761 seq (y) =ack (x) 999 Ack (y) =Seq (y)+1381 (data len) 2761 s--"CThe sequence number in the data fragment ensures that all transmitted data is reorganized in the normal order, and that the integrity of the data transmission is guaranteed.The increase in Seqnum is related to the number of bytes transferred . , after three handshakes, two len:1381 packets were made, and the seqnum of the second package became 1381. Then the first ACK back is 1381, indicating that the

Wireshark packet capture Analysis of TCP establishment and disconnection Process 1. Establish a connection over TCP Note: In this figure, Hosta acts as the client and hostb acts as the server. TCP is the transport layer protocol in the Internet. It uses the three-way handshake protocol to establish a connection. When

A problem found:The server is a Linux system, with JMeter test interface, found to open a lot of TCP connections, [[email protected] bin]# ulimit-n 65535 with this command set the total number of connections, when the pressure test, the number of connections may reach more than 50000, Easily error-prone; View the number of TCP in each state:Netstat-an | awk '/^tcp