Proxy Auto Configuration Files Overview

A proxy auto configuration file instructs a web browser to forward traffic to a proxy server instead of the destination server. Depending on the proxy auto configuration file configuration, the traffic destination can be a proxy server or a real content server.

A proxy auto configuration file contains several mappings between the source, destination and the next hop, such as:

• Source IP subnets and their proxy servers.

• Destination domains and URLs and their proxy servers.

• Source IP subnets that are not to be proxied.

• Destination domains and URLs that are not to be proxied.

The file might also contain other parameters that specify when and under what circumstances a web browser forwards traffic to the proxy server. For example, a proxy auto configuration file can contain instructions about specific days and hours when traffic is sent to the proxy server, along with the domains and URLs for which the traffic is not sent to the proxy server.

All web browsers support proxy auto configuration files. You can configure the URL of a proxy configuration file in web browsers using which the web browsers fetch the file and execute the instructions specified in the file. Proxy auto configuration files can be hosted on a computer, an internal server, or on an external server. Juniper Security Director Cloud hosts a default, recommended PAC file that uses geolocation technology to forward traffic to Juniper Secure Edge.

When you create a new organization in Juniper Security Director Cloud, a recommended proxy auto configuration file is automatically generated. You can download the configuration file or clone and edit the file. You cannot edit the original, recommended proxy auto configuration file, but you can delete the recommended file and generate new recommended files.