[squid-users] Experiences with WPAD and Autoproxy scripts

Hi Squid users,

Mark Reynolds covers use of WPAD in Section 5 of the FAQ and asks for any
comments to be posted back to the group.
I started with Mark's instructions, and found I had to do some extra work,
so for anybody who is interested, here are my comments:

First some notes about our environment: clients on win9x and win2k,
squid2.5Stable3(+WCCP) proxy servers, IIS5 internal web servers, Bind 9 DNS
running under NT4. Until now, I only transparently proxied using WCCP
because I couldn't get WPAD or autoproxy scripts to work reliably within the
initial time constraints of our IE5 rollout (500+ PCs), although all builds
went out with the "automatically detect settings" checkbox ticked, ready for
a time when it could be used.

My main problem has been with broken Netscape autoproxy functions on some
Win2K workstations, in particular MyIPAddress() which for us is essential to
allocating clients from different subnets to different squid proxies.
Microsoft haven't supplied a fix for this (q816941 among others implicate
winhttp.dll and .NET) that worked for us, so I wrote an ASP script to get
the client IP address from server variables and spit out a basic proxy.pac
file with just the PROXY line. (CGI delivery is permitted by the Netscape
standard).

Having stored this asp script on my internal IIS5 server as wpad.dat, I then
set up an application extension mapping .dat files to the same process as
.asp files.

The other problem (WPAD not working) was resolved by testing with Ethereal
against an IE6 client. This showed that the wpad.dat GET request puts the IP
address into the header and not the wpad hostname as I had expected, so once
I had set up a new host header for the default site with the IP address as
the host name, it all works as expected.

Thankyou to all who have provided so much help on this newsgroup

Phil DG

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Received on Fri Jul 25 2003 - 07:48:04 MDT