Introduced
Your WEB server believes that the HTTP data stream sent by a client (such as your browser or our Checkupdown robot) contains an "expected" request that cannot be met. The expected request is fairly generic, that is, there is only a loose definition in the HTTP protocol. It can specify more than one expected value, and different WEB servers may have different interpretations of each expected value.
417 errors in the HTTP loop
Any client (such as your browser or our Checkupdown robot) needs to get an IP address from the IP name of your site (that is, the URL of your site-url, without the start of ' http://'). This correspondence (that is, the correspondence between IP names and IP address conversions) is provided by the Domain name server (DNSS). Open an IP socket (socket) to connect to the IP address. Writes an HTTP data stream through this socket. The HTTP data stream that receives the response from your Web server. The data flow includes a state encoding whose value depends on the HTTP protocol. Resolves the data stream to obtain status codes and other useful information.
This error is generated in the last step described above, that is, when the client receives an HTTP status code and recognizes it as ' 417 '
Resolve 417 Errors-general method
This error rarely occurs in most network transmissions, especially when the client system is a browser. This type of network transport rarely uses "expected" requests.
If your client system is not a browser, this problem can only be resolved by first checking what the client is trying to do, and then discussing with your Internet service provider (ISP) Why the Web server is unable to meet the "expected" requests sent by the client.
Resolve 417 Error –checkupdown
This error should never happen on your Checkupdown account. If it does, it usually indicates that our system or the Web server system that manages your Web site is flawed in programming. We do not use the expected request at all, because we always want to get the full content of the URL you requested us to monitor – without any preconditions.
Whenever you encounter a 417 error, please contact us (preferably via email)-You cannot resolve such errors yourself. We must contact your ISP and Web Server software vendor to confirm the exact cause of the error.
The main look is not the IP configuration has certain permissions, I encountered this problem, that is, access to the server has the right to configure, the current test of the machine IP is not within the scope of the configuration.