PAC Files User Guide Overview

This document describes how to use a Proxy Auto Configuration (PAC) file with the Web Security Service.

A PAC file defines how browsers will direct web traffic through a proxy server for specific URLs. For example, a PAC file can specify direct connections to local Intranet sites, while redirecting all other sites through the Web Security Service and its policies.

There are numerous options for using a PAC file, since its rules are defined by JavaScript.

• Before you begin, review our recommendations for creating and using PAC files:
• Use a PAC file when you have reached the browser bypass limitation of 2,000 characters. This is a browser limitation, and is not related to Web Security Service.
• Move all browser bypasses into the PAC file. Do not attempt to use both browser bypasses and a PAC file, as it can affect browser behavior and can cause administrators some confusion when maintaining bypass entries.
• Always make a backup copy of the contents of the PAC file configuration before making changes. Also, we recommend making your modifications in a separate text file, then pasting them into the PAC file field in the Management Portal of the Web Security Service when you are finished. You can revert to the backup if an incorrectly modified entry causes bypasses to fail.
• If needed, enter domain names, IP addresses, or FTP sites in the PAC file.

• If needed, use a wildcard character, an asterisk (*) to allow for subdomains and other uses, for example:

  *domain.com*

  http://domain.com*

  https://domain.com*

  http://www.domain.com*

  *ftp.domain.net*

  http://200.0.0.0*

  *200.0.0.0*

  200.0.0.*

  ftp://domain.com*

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