Proxy

## Proxy

Krishna Tateneni `<tateneni@pluto.njcc.com>`

Revision Frameworks 5.29 (2016-11-10)

## Proxies

### Introduction

Proxies are programs running on a computer that acts a server on the network you are connected to (whether by modem or other means). These programs receive HTTP and FTP requests, retrieve the relevant files from the internet, and pass them on to the client computer that made the requests.

When you have configured a proxy, HTTP and/or FTP requests are re-routed through the computer that is acting as a proxy server. However, you can also select specific hosts which should be contacted directly, rather than through the proxy server. If you are on a local network, for example, access to local hosts probably doesn't need to go through a proxy server.

You should only need to configure a proxy server if your network administrator requires it (if you are a dial-up user, that would be your internet service provider or ISP). Otherwise, especially if you are feeling a bit confused about this proxy business, but everything seems to be fine with your internet connection, you don't need to change anything.

Please note that using proxy servers is optional, but has the benefit or advantage of giving you faster access to data on the internet.

If you are uncertain whether or not you need to use a proxy server to connect to the internet, please consult with your internet service provider's setup guide or your system administrator.

### Use

No Proxy

  Select this option if you do not want to use a proxy server and connect to the Internet directly.

If you have decided to use a proxy, you have several methods to configure the settings for it.

Detect proxy configuration automatically

  Select this option if you want the proxy setup configuration script file to be automatically detected and downloaded.

  This option only differs from the next choice in that it does not require you to supply the location of the configuration script file. Instead, it will be automatically downloaded using “Web Proxy Auto-Discovery” (WPAD) protocol.

Use proxy auto configuration URL:

  Select this option if your proxy support is provided through a script file located at a specific address. You can then enter the address in the location text box, or use the folder icon to browse to it.

Use system proxy configuration:

  Some systems are setup with $`HTTP_PROXY` to allow graphical as well as non-graphical applications to share the same proxy configuration information.

  If you know this applies to you, select this option and click on the Auto Detect button to provide the environment variable names used to set the address of the proxy server(s).

  In the Exceptions: field enter the environment variable, e.g. $`NO_PROXY`, used to store the addresses of sites for which the proxy server should not be used.

  Use Show the value of the environment variables to show the value of an environment variable instead of its name. However it is not possible to edit the values of environment variables in this module.

Use manually specified proxy configuration:

  The complete addressing information for the proxy includes both the Internet address and a port number. You should enter these into the relevant text boxes. Check Use this proxy server for all protocols to copy the addresses and port of the HTTP proxy server into all other proxy fields, in order to help save some typing.

  Exceptions:

    Enter a comma separated list of hostnames or ip addresses that should be excluded from using the above proxy settings. If you want to exclude all hosts for a given domain, then simply enter the domain name preceded by a dot. For example, to exclude all hostnames for kde.org, enter `.kde.org`. Wildcard characters such as `*` or `?` are not supported and will have no effect. Additionally, you can also enter IP addresses, e.g. 127.0.0.1 and IP addresses with a subnet, e.g. 192.168.0.1/24.

  You can also choose Use proxy settings only for addresses in the Exceptions list.

  Check this box to reverse the use of the exception list, i.e. the proxy servers will only be used when the requested URL matches one of the addresses listed here.

  This feature is useful if all you need is a proxy to access a few specific sites, for example, an internal intranet. If you have more complex requirements you might want to use a configuration script.