[squid-users] Proxy hierarchy and FTP access

[Amos Jeffries]

On 28/02/18 21:30, Grey wrote:
> 
> At this point, I'd like to know if what I'm trying to do is possible at all,
> beacuse I'm starting to think there's something major I've totally
> overlooked.


The most obvious thing is that the port 3128 is an *HTTP* port, so when
the Browser is using that port it is using HTTP protocol to

 a) request that Squid perform all the FTP things and deliver the result
as an HTTP response, or

 b) create tunnels through the proxy to the relevant FTP IP:port of the
origin servers.


By comparison the ftp_port receives FTP protocol natively. Squid is
mapping that FTP protocol messages into HTTP and handling the mapped
requests.

IIRC these mapping requests are only handling internally by the same
Squid that created them. The outgoing is mapped back to FTP for the
server contact. I used to think those requests could go to a cache_peer,
but Alex indicated recently that they do not.

It is technically possible to be done with a few additions to Squid. But
those additions are not present in any current version.

Amos