Alt-Used
The Alt-Used
HTTP header is used in requests to identify the alternative service in use, just as the Host
HTTP header field identifies the host and port of the origin.
The is intended to allow alternative services to detect loops, differentiate traffic for purposes of load balancing, and generally to ensure that it is possible to identify the intended destination of traffic, since introducing this information after a protocol is in use has proven to be problematic.
When a client uses an alternative service for a request, it can indicate this to the server using the Alt-Used
HTTP header.
Syntax
http
Alt-Used: <host>:<port>
Directives
Examples
http
Alt-Used: alternate.example.net
Specifications
Specification |
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HTTP Alternative Services |