505 errors in the HTTP cycle:
This article illustrates the 505 error. If any of the clients go through the following cycle when it communicates with the Web server:
- Obtain an IP address from the IP name of the site (the site URL without the leading ‘HTTP://’). This lookup (conversion of IP name to IP address) is provided by domain name servers (DNS).
- Open an IP socket connection to that IP address.
- Write an HTTP data stream through that socket
- It receives an HTTP data stream back from the Web server in response. This data stream contains status codes whose values are determined by the HTTP protocol. It parses this data stream for status codes and other useful information.
The server refuses to support the HTTP protocol that the client computer specifies. This 505 error occurs if the client computer does not correctly specify the protocol (for example, if it specifies an invalid version number).
This error should not occur if you have a current installation of cPanel & WHM.