## ProxyVia

Syntax: ProxyVia { off | on | full | block }
Default: ProxyVia off
Context: server config, virtual host
Override: Not applicable
Status: Base
Module: mod_proxy
Compatibility: ProxyVia is only available in Apache 1.3.2 and later.

This directive controls the use of the `Via:` HTTP header by the proxy. Its intended use is to control the flow of of proxy requests along a chain of proxy servers. See RFC2068 (HTTP/1.1) for an explanation of `Via:` header lines.

- If set to off, which is the default, no special processing is performed. If a request or reply contains a `Via:` header, it is passed through unchanged.
- If set to on, each request and reply will get a `Via:` header line added for the current host.
- If set to full, each generated `Via:` header line will additionally have the Apache server version shown as a `Via:` comment field.
- If set to block, every proxy request will have all its `Via:` header lines removed. No new `Via:` header will be generated.