End-to-end and Hop-by-hop Headers ---nginx-websocket

时间:2020-12-31 11:44:42

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13.5.1 End-to-end and Hop-by-hop Headers

 

For the purpose of defining the behavior of caches and non-caching proxies, we divide HTTP headers into two categories:

 

  • End-to-end headers, which must be transmitted to the ultimate recipient of a request or response. End-to-end headers in responses must be stored as part of a cache entry and transmitted in any response formed from a cache entry.

     

  • Hop-by-hop headers, which are meaningful only for a single transport-level connection, and are not stored by caches or forwarded by proxies.

The following HTTP/1.1 headers are hop-by-hop headers:

 

  • Connection
  • Keep-Alive
  • Public
  • Proxy-Authenticate
  • Transfer-Encoding
  • Upgrade

All other headers defined by HTTP/1.1 are end-to-end headers.

Hop-by-hop headers introduced in future versions of HTTP MUST be listed in a Connection header, as described in section 14.10.