Front desk · HTTP Status Codes
5×× Server Error
511 Network Authentication Required
· filed 2026-07-18 · click a code to copy
HTTP 511 Network Authentication Required is a server error-class status code defined in RFC6585. Network authentication is required — typically a captive portal (hotel/airport Wi-Fi).
Server-error responses admit the fault is on the server's side: the request was valid, but the server failed to fulfil it. On the wire, the response begins with the status line HTTP/1.1 511 Network Authentication Required.