Status Codes

Status codes only come from a server that responds. Which server exactly may not be apparent, but reviewing the status codes can help you understand what is responding.

By testing both localhost and from another server, you can narrow down if it is an application issue or some type of ACL or route issue.

Curl Status Codes

curl -sI localhost:80 | grep HTTP
HTTP/1.1 302 Found

Bypass Self Signed Certificate

curl -sI -k https://yoursite.com:443 | grep HTTP
HTTP/1.1 200 OK

List of Status Codes

Status Code	Explanation & Diagnosis Tips
200 OK	The request was successful. This is the standard response for successful HTTP requests.
301 Moved Permanently	The requested resource has been moved permanently to a new URI. Update your links or bookmarks to the new URI.
302 Found	The requested resource is temporarily under a different URI. As this is temporary, the original URI should be used again in future requests.
304 Not Modified	The resource has not been modified since the last request. Useful for caching and bandwidth-saving purposes.
401 Unauthorized	The request requires user authentication. Check if the request includes proper authentication credentials.
403 Forbidden	The server understood the request but refuses to authorize it. Check user permissions and server configuration.
404 Not Found	The server cannot find the requested resource. Check if the URL is correct.
500 Internal Server Error	A generic error message when the server encounters an unexpected condition. Check server logs for specific details.
502 Bad Gateway	The server received an invalid response from the upstream server. Check the configuration and health of upstream servers.
503 Service Unavailable	The server is currently unavailable (due to overload or maintenance). Often temporary, so try the request again later.
504 Gateway Timeout	The upstream server failed to send a request in the time allowed by the server. Check network and upstream server issues.