HTTP 501 error-not implemented (not implemented)

Introduction

Your web server does not understand or support the HTTP method it finds in the HTTP data stream sent to a client (such as your browser or our checkupdown robot. The methods defined in HTTP are as follows:

• Options: Find the communication options that apply to resources of a specific website. Allows the client to determine resource-related options and/or requirements, or the performance of a server, without performing specific actions involving data transmission.
• Get: retrieves information determined by the website resources, such as a specific webpage or image. This is the most common method.
• Head (header): Besides the header information provided by the server rather than the information determined by the website resource, it is basically the same as get (get ). It can be used to obtain the metadata of the response entity required by a request, without transmitting the response entity itself. It is often used to test the validity, accessibility, and recent modifications of hypertext links.
• Post (posting): submit data to a Web server, for example, 1) send information to the bulletin board, newsgroup, or to the email list, 2) provide input data-generally, a Common Gateway Interface (CGI) Table is used to process data. 3) records are directly added to a database.
• Put: Set (put/replace) the data of a specific website to the new data submitted by the customer. For example, upload a new webpage to the server.
• Delete: delete data related to the website resources. For example, delete a webpage.
• Trace: A Remote Application Layer delivery that runs the request information. It is actually a 'ping' to test what data the Web server is receiving from the client.
• Connect (connection): retained for use (such as SSL) through proxy servers and tunnels ). This method is defined only in HTTP 1.1, but not in earlier 1.0.

If the request method in the HTTP data stream is not one of the above, it will cause 501 error. Or the method may be valid but not supported by your web server. This usually only happens when a new method is used, such as when the old web server receives the connect method.

Error 501 in HTTP Loop

Any client (such as your browser or our checkupdown robot) communicates with your network server through the following cycle:

• Obtain an IP address from the IP address of your site (that is, the URL of your site, without the starting 'HTTP. This ing relationship is provided by the Domain Name Server (DNSS.
• Open an IP socket to connect to the IP address.
• Write the HTTP data stream through this socket.
• Accept the response HTTP data streams from your web server. This data stream includes status encoding, and its value depends on the HTTP protocol. Parse the data stream to get status code and other useful information.

This error is generated in the last step described above, that is, when the client receives the HTTP status code and recognizes it as '123.

Solution to 501 error-General Method

This error should be rare in any browser. If the client is not a browser, it is more likely-especially if the web server is old. In both cases, if the client specifies a valid request type, the web server needs to be upgraded either because the response is incorrect.