Today we will talk about the role of DNS, how DNS affects the Internet, and the DNS problems of Internet access in mainland China.
An IP address in the online world is equivalent to a house number. With an IP address, you can access network resources. But it is a string of numbers that is difficult to remember, so there is a domain name, and DNS is a service responsible for converting domain names (such as google.com) into IP addresses (such as 172.217.160.110)
From the above, we can see that if the resolution returns the correct IP address quickly, it is a good DNS service. On the contrary, if the speed is slow or even the wrong IP is returned, it will affect the Internet access.
Generally speaking, if the user has no special settings, the network operator (ISP) will provide a default DNS service, and the user can access the Internet normally without setting it. World-renowned Internet companies also provide DNS services for everyone to use for free, such as:
Google's DNS: 8.8.8.8, 4.4.4.4
CloudFlare's DNS: 1.1.1.1, 1.0.0.1
Alibaba's DNS: 223.5.5.5, 223.6. 6.6
Simply put, DNS returns the wrong IP to you, preventing you from browsing the website normally. In addition to the well-known domain name blocking by the Great Firewall of China, some operators will randomly block overseas domain names that have not been blocked, and some rogue operators will even use DNS hijacking to distribute advertisements. Among the three major operators, #China Mobile has more serious pollution, and is also known as the mobile wall within a wall. We recommend that friends who use #mobile broadband can modify their DNS and use Alibaba instead (you can Google DNS modification instructions by yourself).
Unfortunately, Google, CloudFlare, or other overseas DNS services are subject to firewall interference and are not suitable for use in China.
Change Alibaba DNS on iPhone:
Shadowrocket automatically adds DNS tutorial
Change Alibaba DNS on Windows/Mac:
https://www.shangyouw.cn/shezhi/arc23158.html
Change Alibaba DNS on Android: (Click in and slide to the bottom to see the picture settings)
https://alidns.com/articles/6018321800a44d0e45e90d71