[KLUG Members] Re: DNS and IPCop

[Adam Williams]

> Wow, I was wrong! Man, whatever you do, don't tell my wifal unit! :)

How much is it worth to you? :)

> OK, I understand what you're doing and that's agreeable. But you explicitly 
> configured the proxy setting. I *think*, if I recall earlier messages in this 
> thread (it's getting a little difficult to follow now), he didn't want to 
> configure clients to access the proxy, which would mean he wants transparent 
> proxy. That being the case, web traffic is scooped off the wire by the proxy 
> on its way out...transparently...so the client would have to have default 
> gateway & DNS info handed to it, right? How else will it know where to go?

Yes, transparent proxy requires DNS to be operable.  A static proxy can
make most things work without DNS.  BUT you will discover Active X,
VBScript, and Java Appletts that will not work;  specifically if they
want to make a network connection somewhere (a java SSH/telnet applett
for example).

> Otherwise, based on the results you report, I reckon default gw & DNS info are 
> not required at the client. Thank you for clarifying that, because I am in the 
> process of ditching squid on IPCop and running it on a different box and not 
> transparently. I would have gone through the trouble of handing out that extra 
> info when I didn't need to. So, thanks for saving me some effort!

If you add -
option wpad-url code 252 = text;
option wpad-url "http://wpad.morrison.iserv.net/wpad.dat";
- to the DHCP configuration IE will load the proxy configuration from
that file, thus auto-discovering the relevant settings.

This file simply contains a javascript function that the browser
executes, like:
-----------------------------------------------------------------------
function FindProxyForURL(url, host)
{
  if (url.substring(0, 5) == "http:") {
       return "PROXY kohocton.morrison.iserv.net:3128; DIRECT";
  }
  else if (url.substring(0, 4) == "ftp:") {
       return "PROXY kohocton.morrison.iserv.net:3128; DIRECT";
  }
  else if (url.substring(0, 7) == "gopher:") {
       return "PROXY kohocton.morrison.iserv.net:3128; DIRECT";
  }
  else if (url.substring(0, 6) == "https:" || url.substring(0, 6) ==
"snews:") {       return "PROXY kohocton.morrison.iserv.net:3128; 
DIRECT";
  }
  else {
        return "DIRECT";
  }
}
---------------------------------------------------------------------

I don't know if there is a way to make Mozilla automatically aquire
these settings.  It sure would be nice if there was.

I sym-link wpad.da to wpad.dat since some versions of IE seem to try to
load the provided URL minus one character.