Although I tried several times mirroring Microsoft Windows Update using free
software I did not the solution; I looked at in Squid ML archives and other
documentations on web but resolving nothing. I'm going to use Squid
Accelerator. My aim is to reach MS windows update from whatever client in
the lan because only some of them can download MS patches infact their
browsers are set to go out in Internet (privileged users).

I configured Squid Accelerator to listen to 80 port, with proxy option no
httpd_accel_host virtual
httpd_accel_with_proxy off
httpd_accel_single_host off

I installed 2 NIC in Squid Accelerator Server : internal and public network:
3 virtual ip addresses for internal Network Interface Card,
1 ip address for public Network Interface Card.

In this way I can use a redirector script (written in PERL) to associate
virtual ip address to these sites:

When I access , for instance, to my browser correctly point to but after few minutes I can see this error:
no route to host. I must say that there's specified the DNS on Squid

Problem is only for Windows Update site.
Are there problems with Windows Update Javascript ?
Could it be caused because there is attempt to use HTTPS ?!

I noted that using a simple Squid (to go out in Internet) acting as
cache-server (no configured as accelerator) and I set my browser to use it,
I have no problem to run W.U. and download patches.
I'm able to understand the "difference" about how they works and if there
is difference how MS W.U. takes care answers toward Squid and Squid