Explanation of the meaning and reason of 404 Not Found

What does 404 Not found mean? Why does it appear 404 Not Found?

The meaning of 404 Not Found:

404 Not Found is a standard HTTP return code that, when a user enters a link, the IIS (Internet Information Services) on the server first detects whether the user-entered address link has the corresponding page information, and if there is no corresponding page information, Indicates that the user entered an invalid string of links, and IIS sends a 404 error code page hint to the end user via the server telling the user that the page information that corresponds to the address link is not found. In the Chinese web environment if the 404 return page for the Chinese and reasonable optimization, let users know the first time they input errors, through the optimization of the 404 pages to guide users into the correct link, rather than immediately leave the site, you can say 404 Not found the appearance of greatly improve the user experience degree, Use a friendlier way to face the user.

Reason for 404 Not Found:

First: The user entered an address link incorrectly, causing IIS to prompt 404 Not found.

The second type: The server should have been deleted, this situation in BBS forum, n years ago The post is now you through search engine search out, but in fact BBS forum in order to protect the resources of the server reasonable use, will be outdated or very remote information page deleted, resulting in 404 Not Found

Third: DNS settings to block, in terms of Chinese environment, there are some banned sites in China to browse the same phenomenon of 404 Not Found, which requires the use of Proxy server to normal browsing.

From a professional point of view, the cause of three kinds of reasons:

1, unable to access the Web site on the requested port.

2. The Web service extension lockout policy blocks this request.

3. The MIME mapping policy prevents this request.

In short, the 404 Not Found error page is intended only to prompt the user, not the symptom, and it is friendly to prompt the user that the page cannot be accessed.