511 Network Authentication Required

Estimated reading: 2 minutes 555 views

This error response indicates the client must authenticate to gain network privileges.

Network operators may require authentication, terms and conditions, or other types of user engagement before granting access.

Instead of the origin server, this error is generated by a ‘capture portal’, or proxy, that controls access to the network. Users would most often see this with public WiFi services, such as at an airport or coffee shop.

Identification of the client with this type of access is often used with a MAC address.

Following the instruction provided by the network operations should resolve the error. If the error persists despite following the requirements then the user should request help from the network operator.

The HTTP 511 Network Authentication Required response status code indicates that the client needs to authenticate to gain network access.

This status is not generated by origin servers, but by intercepting proxies that control access to the network.

Network operators sometimes require some authentication, acceptance of terms, or other user interaction before granting access (for example in an internet café or at an airport). They often identify clients who have not done so using their Media Access Control (MAC) addresses.


511 Network Authentication Required


RFC 6585, section 6: 511 Network Authentication RequiredAdditional HTTP Status Codes