wpad method, web proxy auto discovery.

Greetings.

Having just read about and implemented the Web Proxy Auto-Discovery Protocol
I thought I'd document the process, while I still remember.

FAQ maintainer, please feel free to add this in with any other changes needed.

You may like to start by reading the draft ...
http://www.ietf.org/internet-drafts/draft-ietf-wrec-wpad-01.txt

After reading the 8 steps below, if you don't understand any of the
terms or methods mentioned, you probably shouldn't be doing this.
Implementing wpad requires you to _fully_ understand :
  1. web server installations and modifications.
  2. squid proxy server (or others) installation etc.
  3. Domain Name System maintenance etc.
Please don't bombard the squid list with web server or dns questions. See
your system administrator, or do some more research on those topics.

This is not a recommendation for any product or version. As far as I
know IE5 is the only browser out now implementing wpad. I think wpad
is an excellent feature that will return several hours of life per month.
Hopefully, all browser clients will implement it as well. But it will take
years for all the older browsers to fade away though.

I have only focused on the domain name method, to the exclusion of the
DHCP method. I think the dns method might be easier for most people.
I don't currently, and may never, fully understand wpad and IE5, but this
method worked for me. It _may_ work for you.

But if you'd rather just have a go ...

1. Create a standard netscape auto proxy config file, as detailed
   in the FAQ. http://squid.nlanr.net/Squid/FAQ/FAQ-5.html
   The sample provided there is more than adequate to get you going.
   No doubt all the other load balancing and backup scripts will be fine also.

2. Store the resultant file in the document root directory of a handy
   web server as wpad.dat (Not proxy.pac as you may have previously done.)

3. If you do nothing more, a url like http://www.your.domain.name/wpad.dat
   should bring up the script text in your browser window.

4. Insert the following entry into your web server mime.types file.
   Maybe in addition to your pac file type, if you've done this before.
   application/x-ns-proxy-autoconfig dat
   And then restart your web server, for new mime type to work.

5. Assuming Internet Explorer 5, under Tools, Internet Options, Connections,
   Settings _or_ Lan Settings, set _ONLY_ Use Automatic Configuration Script
   to be the URL for where your new wpad.dat file can be found.
   ie http://www.your.domain.name/wpad.dat
   Test that that all works as per your script and network.
   There's no point continuing until this works ...

6. Create/ instal/ implement a DNS record so that wpad.your.domain.name
   resolves to the host above where you have a functioning auto config
   script running. You should now be able to use
   http://wpad.your.domain.name/wpad.dat as the Auto Config Script
   location in step 5 above.

7. And finally, go back to the setup screen detailed in 5 above, and
   choose nothing but the 'Automatically Detect Settings' option, turning
   everything else off. Best to restart IE5, as you normally do with any
   Microsoft product... And it should all work. Did for me anyway.

8. One final question might be 'Which domain name does the client (IE5) use
   for the wpad... lookup?' I think it is determined after doing a reverse
   DNS lookup on the allocated IP number. Else it might use the default
   domain name... Not sure. Might require reverse lookup tables for all
   dialup IP number ranges, which is a good thing anyways.

Anybody using these steps to install and test, please feel free to make
notes, corrections or additions for improvements, and post back to the
squid list...

There are probably many more tricks and tips which hopefully will be
detailed here in the future. Things like wpad.dat files being served
from the proxy server themselves, maybe with a round robin dns setup
for the wpad host.

___________________________________________________________________________

Mark Reynolds mailto:mark@rts.com.au Phone 08 9474 1211
Network Manager, Reynolds Technology Pty Ltd Fax 08 9474 4772
Office: 8 Preston Street Como 6152 Western Australia Pager 08 9480 5884
Postal: PO Box 120 Como 6952 Western Australia http://www.rts.com.au
___________________________________________________________________________

"In the end, Australia's blue-nosed politicos are likely to learn the hard
way that, whether they like it or not, free speech is here to stay. It's
too bad that the Australian people will have to pay the expensive price for
that lesson." http://civilliberty.about.com/library/weekly/aa062199.htm
___________________________________________________________________________
Received on Sat Jul 31 1999 - 22:03:56 MDT