HTTP 400 ERROR-Invalid request

Source: Internet
Author: User
Tags domain name server


Your Web server believes that the data stream sent by the client (for example, your browser or our CheckUpDown robot) is ' malformed ' and that it does not fully comply with the HTTP protocol. Therefore, your WEB server is unable to understand and process the request.

This error almost always means that the client system and/or your Web server programming fails.

Resolve 400 Errors – General method

There is a low-level program Vulnerability (bug) on the client or Web server, or both ends. If you are unable to access the source programs for these systems, the only thing you can do is to submit the issue to the technical support staff of the company that developed the systems.

Resolve 400 Error –checkupdown

And found an error similar to 400. You should not see this error at all when using our CheckUpDown service. It shows that two systems (our robots and your Web servers) are fundamentally inconsistent in the HTTP data flow syntax.

As long as you encounter 400 errors, please contact us directly (preferably using email). Only we can solve this kind of problem for you. Unfortunately this may take some time, as we must analyze the relevant HTTP traffic and perhaps contact your ISP and the vendor of the Web server software to confirm the exact source of the error.

400 errors in the HTTP loop

Any client, such as your browser or our CheckUpDown robot, will have to go through the following loops when communicating with your Web server:

    1. Obtain an IP address from your site's IP name (that is, your Web page address-URL, without the start of ' http://'). This correspondence (that is, the correspondence between IP names to IP addresses) is provided by the Domain name server (DNSS).
    2. Open an IP socket (socket) to connect to the IP address.
    3. Writes the HTTP data stream through the socket.
    4. The HTTP data stream that receives the response from your network server. The data stream includes a status code whose value depends on the HTTP protocol. Parse the data stream to get status coding and other useful information.

This error is generated in the last step described above, when the client receives an HTTP status code and recognizes it as ' 400 '.

HTTP 400 ERROR-Invalid request

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.