Official Toolset

Overview

The FindProxyForURL.com Toolset is designed to bring transparency and clarity to PAC / WPAD deployments when troubleshooting

A few examples of how the tool is great for troubleshooting include whether a PAC file is being pushed with the correct MIME type, whether the PAC file has valid syntax, which URL is being pushed out by WPAD DHCP, or whether WPAD DNS can locate the PAC file.

Any PAC files found are automatically downloaded and tested while any WPAD DNS/DHCP values, usually difficult to discern, are collected and reported.

With administrator privileges, the Toolset is supported on Windows Vista or later, and Windows Server 2003 and later.

Download

Download FindProxyForURL Toolset – version 1.0
Last updated: 10/30/2014

Deployment

  • Extract the ZIP contents to a folder
  • Run Deploy_Toolset.bat and the toolset will perform its operations and once complete open the data file.

Documentation

Internet Explorer Configuration

This tool reports the status of the configuration for the Internet Explorer Automatically Detect Settings and Use Automatic Configuration script setting.

If the Use Automatic Configuration script setting is enabled, the tool will attempt to download and validate the PAC file. See the PAC File Testing section below for more information.

Note: The tool determines these settings by reading the Windows Registry, thus if this section reports a fatal error, it may be due to a lack of the necessary permissions for accessing the Windows Registry.

WPAD DHCP Configuration

This tool will report whether a DHCP 252 option containing a PAC file URL is being deployed to the machine.

If a DHCP 252 option is found, the tool will attempt to download and validate the PAC file. See the PAC File Testing section below for more information.

WPAD DNS Configuration

This tool will report whether it’s able to guess the PAC file location using the WPAD DNS mechanism (e.g. prefix the DNS search host with wpad and suffix with /wpad.dat)

The tool relies on the same DNS suffix settings a browser would; these settings can be observed by running ipconfig /all from a command prompt and reviewing the Primary Dns Suffix and DNS Suffix Search List configuration.

If a wpad host is found, the tool will attempt to download and validate the PAC file. See the PAC File Testing section below for more information.

Note: In some cases the same DNS host may be tested twice, this is due to it appearing in both the Primary DNS Suffix and DNS Suffix Search List configuration.

PAC File Testing

For each PAC file found, be it deployed via WPAD or an explicit configuration, the tool will perform the following actions and report the status:

  • The URL of the PAC file
  • Whether the PAC file is accessible
  • The content type returned for the PAC file
  • Whether the PAC file successfully validates using the pacparser tool

Please note the following:

  • There is no 100% reliable PAC file syntax validation tool currently available, thus you should always review the PAC file for syntax and rule issues visually.
  • Local PAC files are unsupported.

Error Messages

  • Unable to identify Automatically Detect Settings status
    The tool was unable to read the Windows Registry, ensure the Windows permissions allow Registry access.
  • No DNS Suffixes found for WPAD DNS search
    The machine most likely has a manually configured network adaptor and requires a DNS search suffix be configured. Most IT organizations have a common DNS host to perform local host resolution against, e.g. entering intranet into your browser will function just as well as intranet.corp.com; this is because corp.com is configured as a DNS search suffix for your network adaptor.