If the page is inaccessible, it is not called 404 Not Found

. If you are still unable to access all the pages, it is called “404 Not Found”, then you need to update your knowledge base. “404 Not Found""404” The official name is the HTTP Status Code, which is used to indicate the response status of the web server HTTP. The first digit of the 3-digit code represents the status of the response and is divided into five states, from 1xx to 5xx, representing web page response processing, success, redirection, client error, and server error. Where 404 refers to the request failure, and the resource that the request is expected to be undiscovered on the server. As for what is not discovered, further inquiries may be required. So, you might ask, what do you see when you visit Twitter, Facebook, and other non-existent websites? Normally, what we mean is “by wall”, the page will display error 502, 504 or 500. 500 Internal Server Error means that the server encountered an unexpected situation, which caused it to complete the processing of the request. . 502 Bad Gateway means that when a server working as a gateway or proxy attempts to execute a request, it receives an invalid response from the upstream server. 504 Gateway Timeout means that when a server working as a gateway or proxy attempts to execute a request, it fails to receive a response from the upstream server (the server identified by the URI, such as HTTP, FTP, LDAP) or the secondary server (for example, DNS). Didn't understand, it doesn't matter, remember one sentence: 404 Not Found means that the website is not walled. 404 Not Found means that the website is not walled. Very important, so say it twice. If you want to get a deeper understanding of the different response states of web pages, you can try to tell what these two graphs represent. Figure 1: Figure 2: This article comes from [system home] www.xp85.com Related articles recommended: 1.404 What a hell! How much do you know about 404? 2. What does the error 405 error appear on the web page? 3. The solution that the webpage cannot be opened