464 Incompatible protocol
The 464 HTTP response status code means that the AWS Elastic Load Balancer received an HTTP request with an incompatible protocol.
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Introduction
In Action
Sample
Conclusion
Introduction
When you encounter the HTTP status code 464 “Incompatible Protocol,” it means that the AWS Elastic Load Balancer received an HTTP request with an incompatible protocol.
This error is specific to AWS services and indicates that the load balancer cannot process the request due to protocol mismatches.
In Action
If you encounter the HTTP status code 464 “Incompatible Protocol,” it means that the client has sent an HTTP request that doesn’t match the version configuration of the target group protocol.
For instance, if the request is made using HTTP/1.1, but the target group’s protocol is set to HTTP/2, this error will occur. This is specific to certain AWS services and helps ensure that the communication between the client and server is compatible with the specified protocols. Remember that search engines won’t index URLs with this status code to prevent irrelevant results.
Sample
In the example scenario, when the HTTP client makes a request using the HTTP/1.1 protocol, the server responds with the status code 464 “Incompatible Protocol.”
This indicates that the target group does not support the HTTP/1.1 protocol, and a different protocol must be used for the request to be successfully processed.
Request
GET /tech-news HTTP/1.1
Host: www.example.com
Response
HTTP/1.1 464
Content-Type: text/html
Content-Length: 147
< html>
< head>
< title>AWS Load Balancer Error< /title>
< /head>
< body>
< p>Incompatible protocol. Please use HTTP/2.< /p>
< /body>
< /html>
Conclusion
The 464 “Incompatible Protocol” status code indicates that the HTTP request protocol is not compatible with the target group’s configuration. The server requires a different protocol to process the request successfully, and the client should adjust the protocol accordingly for a valid response.
