Introduction #

Since 2017, “being walled” has become a common experience for many internet users. As online environments and policies have evolved, certain websites or services have been restricted access due to various reasons, leaving users unable to access them normally. This has posed significant challenges for academic research, news access, and online learning.

However, despite these obstacles, there are still methods available to bypass internet censorship, allowing us to continue accessing the rich resources of the internet world.

Introduction #

In modern computer networks, TCP（Transmission Control Protocol）serves as the foundational protocol for internet communication and plays an indispensable role. TCP is not only responsible for reliable data transfer but also ensures network connection stability and efficiency through complex handshakes and flow control mechanisms. It is a connection-oriented, reliable, byte-stream-based transport layer protocol that ensures the reliable transfer of data between various applications.

However, in the design and implementation of the TCP protocol, there is a mechanism that, although important, is often overlooked—TCP Reset (TCP Reset). In certain situations, TCP sends a “reset” (RST) segment to terminate the currently ongoing data transmission, which is commonly referred to as TCP Reset. This mechanism can have significant negative impacts on network security and system stability in some cases. This article will delve into the hazards and implications of TCP Reset and provide a detailed explanation of how to address this issue.

Preface #

In the modern internet ecosystem, the Domain Name System (DNS) is a critical infrastructure that connects users to websites, playing an indispensable role. Simply put, DNS acts like an address book on the internet, converting human-friendly domain names (such as www.example.com) into IP addresses that computers can understand (like 192.168.1.1). However, this seemingly basic function hides a severe security risk. In certain circumstances, DNS servers can be maliciously manipulated or tampered with, leading to interference in user query results—a phenomenon known as DNS poisoning.