Cisco Cisco ScanSafe Wi-Fi Hotspot Security White Paper
Cisco CWS
– Standalone Deployment Guide
5
Test
Deploy
Prepare
Deploy
Redirect web traffic
The following sections will explain how to redirect web traffic to the cloud using a PAC file. PAC files are
used to determine whether to forward a web request to a particular proxy or to send web requests out
directly from the client.
used to determine whether to forward a web request to a particular proxy or to send web requests out
directly from the client.
This document is intended to provide an overview of the deployment process. For more detailed
information and troubleshooting, please refer to the
information and troubleshooting, please refer to the
Configure a PAC file
The inner working of a PAC file is JavaScript. Although no script experience is required to craft a PAC file,
it is beneficial to understand the fundamentals of how JavaScript works.
it is beneficial to understand the fundamentals of how JavaScript works.
Reference video:
JavaScript is a cross-platform scripting language usable on Windows, Mac and Linux. As JavaScript is
case sensitive, one must use caution when creating and modifying PAC files. Any errors in the PAC file
will prevent the PAC file from being read. The browser will simply ignore the PAC file and fail open. A
browser that is failed open acts normally, as if no PAC file was configured in the browser at all.
case sensitive, one must use caution when creating and modifying PAC files. Any errors in the PAC file
will prevent the PAC file from being read. The browser will simply ignore the PAC file and fail open. A
browser that is failed open acts normally, as if no PAC file was configured in the browser at all.
JavaScript Conventions
Description
// (double forward slashes)
a comment; text that is preceded by these characters
will not be read
() (open and closed
parentheses)
parentheses)
contain arguments for a function
{} (curly brackets)
encapsulates arguments and functions within a
function, supersedes parentheses, and cannot be
contained within parentheses
contained within parentheses
|| (double pipes)
a logical OR statement; allows the script to evaluate
more than one condition in a function
; (semi-colon)
ends a function, like the period in a sentence
Chart 2.1
A variable is a means of dynamically representing a numeric character value. A variable’s value may
change each time the PAC file runs.
change each time the PAC file runs.
Declare a variable using the following: var VARIABLE_NAME=SOME_VALUE;
Overview of JavaScript Functions
FindProxyForURL
(
url, host
)
– overall function governing for the PAC file itself. Web browsers look for
this function when configured to use a PAC file. The value for the two variables enclosed by the
parentheses is defined by the browser. You do not need to define them.
parentheses is defined by the browser. You do not need to define them.