TCP three-way handshake and four waved Wireshark packet capture view

TCP three-way handshake to establish a connection

Server side simulation

Client simulation

# 创建TCP套接字
tcp_client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# 客户端连接服务端
tcp_client_socket.connect(("192.168.241.1", 8080))

Wireshark filters tcp ports

tcp.port == 8080

First handshake

The client sends a SYN signal to the server

Second handshake

The server sends a (SYN, ACK) signal from the client

Third handshake

The client sends an ACK signal to the server

TCP waved four times to close the connection

The picture is forwarded from TCP's three-way handshake and four waved hands. Understanding and interview questions (very comprehensive) by青柚_

The client actively closes the connection

tcp_client_socket.close()

Wave for the first time

Second wave

Third wave

Fourth wave