"Automatically Detect Settings" Does Not Work if You Configure DHCP Option 252
| Article ID | : | 307502 |
| Last Review | : | July 16, 2004 |
| Revision | : | 3.1 |
This article was previously published under
Q307502
SYMPTOMS
When you set up proxy settings in Internet
Explorer by using the
Automatically detect settings
setting, the client may fail to receive the
settings from an Internet Security and
Acceleration (ISA) Server. This can happen
even if the client gets the configuration
correctly when you specify the full URL to
the Wpad.dat file by using the
Use automatic
configuration script setting or by
using the Internet Explorer Address
box.
CAUSE
You can set up a DHCP server to use the
option 252 to automatically configure proxy
settings for Internet Explorer clients by
specifying the URL to the server that is
storing this information. The request may
fail if you have configured the scope on the
DHCP server with a capital letter in the URL
that points to the Wpad.dat file, for
example, "http://isaserver:8080/Wpad.dat".
ISA Server is case sensitive and a request
for Wpad.dat does not work because ISA
Server is using wpad.dat.
RESOLUTION
Use all lower cases in the URL when you
configure the scope, for example,
"http://server:8080/wpad.dat".
MORE INFORMATION
For additional information about automatic
discovery, click the article numbers below
to view the articles in the Microsoft
Knowledge Base:
252898
(http://support.microsoft.com/kb/252898/EN-US/)
How to Enable Proxy Autodiscovery in
Windows 2000
296591
(http://support.microsoft.com/kb/296591/EN-US/)
A Description of the Automatic Discovery
Feature
APPLIES TO
| • | Microsoft Internet Explorer 5.5 |
| • | Microsoft Internet Explorer 5.01 |
| • | Microsoft Internet Explorer 5.0 |
| • | Microsoft Internet Explorer 5.5 |
| • | Microsoft Internet Explorer 5.01 |
| • | Microsoft Internet Explorer 5.0 |
| • | Microsoft Internet Explorer 5.5 |
| • | Microsoft Internet Explorer 5.01 |
| • | Microsoft Internet Explorer 5.0 |
| • | Microsoft Internet Explorer 5.5 |
| • | Microsoft Internet Explorer 5.01 |
| • | Microsoft Internet Explorer 5.0 |
| • | Microsoft Internet Explorer 6.0 |
| • | Microsoft Internet Explorer 6.0 |
| • | Microsoft Internet Explorer 6.0 |
| • | Microsoft Internet Explorer 6.0 |
| • | Microsoft Internet Explorer 6.0 |
| • | Microsoft Internet Explorer 6.0 |
| • | Microsoft Internet Information Services 5.0 |
| • | Microsoft Internet Security and Acceleration Server 2000 Standard Edition |