Question : Understanding auto.pac

Hello

In our network we have a set of HTTP Proxies that HTTP traffic passes through. We use an auto.pac file that helps dictate which proxy server a given URL goes through.

I've read the article below, but I am still a little bit confused.

So, we have the following lines in our pac file:

  if ( isPlainHostName( host ) ||
         ( dnsDomainIs(host, "mydomain.com")  
             && host != "www.mydomain.com"
               && host !="www.marketing-mydomain.com"
         dnsDomainIs(host, "media.online.mydomain.com") ||
       shExpMatch(host, "127.0.0.1") )
      {return "DIRECT";}

I'm not sure what return DIRECT means? Does it mean send the URL to the Proxy server, or send the DNS request back to the internal DNS servers?

And, secondly, does the pac file apply to URL accessed via IE only, or any URL's accessed on that machine?

Answer : Understanding auto.pac

Here is documentation:
http://technet.microsoft.com/en-us/library/dd361918.aspx

DIRECT would mean there is NO proxy involved, the browser should translate the name on it's own using a DNS server and then connecto to the DNS-supplied address.
Otherwise it would return something like: "PROXY proxy-server:8080"

The latter depends if the browser supports proxy configuration, Firefox can use it too, my guess is that every serious browser can handle this.
(Firefox: Extra> options> advanced> network> connection> settings)