Do not flow the Connection header?

[Tratcher]

https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.10

The Connection header is per hop and shouldn't be forwarded through a proxy. Note most of the spec concerns here apply to traditional forward proxies, but they might still be useful for a reverse proxy. E.g. Forwarding a Connection: close header would allow the client to terminate the proxy's connection to the destination and negatively impact performance.

Note for WebSockets we do need to forward the Connection: Upgrade header, so we can't ban Connection outright.

[karelz]

Triage: Motivation protect performance - we should filter out Connection: close (we don't have more at the moment).
1.0. because it is DoS problem.

[Tratcher]

Keep-Alive should also be removed from requests. We already remove it from HTTP/2 responses.