[Gllug] how to check for a transparent proxy

[itsbruce at uklinux.net]

On Mon, Dec 02, 2002 at 08:23:44AM +0000, rich at annexia.org wrote:
> > > > Go to http://pdr.me.uk/t.php and find the bit that says "REMOTE_ADDR"
> > > > and if that is your IP then there is no proxying, otherwise the external
> > > > IP of your proxy will be there.
> > > 
> > > A decent transparent proxy will rewrite source addresses, so
> > > this will NOT tell you if there's a transparent proxy in the
> > > way.
> > 
> > This is contradictory.  If it is rewriting source addresses then the
> > REMOTE_ADDR according to the web server WILL be the proxy's.
> 
> No, I meant it would rewrite source addresses on the way out.
> Thus from the p.o.v. of the transparent proxy, the source address
> 127.0.0.1 would be rewritten to the original source address.
> 
> Anyway, it's a moot point

No, you still seem to be confused.  It's very simple.  A transparent
proxy effectively NATs any outgoing connections over the ports diverted
through it.  So a remote page that detects the IP address of the
connecting client will detect and print the proxy ip address.  This text
on the web page *will not* be rewritten by the proxy.

-- 
Bruce

-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug