Configuring Proxy Clients

It’s not enough to just set up a proxy server. You alsoneed to point Internet applications on client machines to make use of this proxyserver. Unfortunately, there is no central place where you can store thisinformation, and have all applications use it. So, you’ll have to configureeach application individually. Here, we’ll look at some of these.

Internet Explorer 5.5

Go to Tools>Internet Options> Connections>LANSettings. You can either check Automatically detect settings or Use a proxyserver. If you choose the latter, in the Address text field type the IP addressor hostname of the machine on which your proxy server is running. In the Portfield, type the port number on which the proxy server is configured.

Using scripts to configure proxy settings

You can also use a script to tell the browser about the proxyconfiguration. Enter the following lines in a text file. Assuming that the proxyserver runs on a machine with the IP address 192.168.1.1 and listens on the port8000:

function FindProxyForURL(url, host)

{

return "PROXY 192.168.1.1:8000";

}

Save the file as script.pac. Now, check Use automaticconfiguration script and in the Address text field enter the path to the scriptfile as:

file://c:\script.pac, if the file has been saved to c:\

Here the script is lying on your local machine. This kind ofconfiguration actually defeats the purpose of automatic configuration, which isto configure the clients from a central location. In real life, you would liketo place the file script.pac on a Web server and then configure your browser topick the file from the Web server. In the case of Apache Web server on Red HatLinux, place script.pac in
/home/httpd/html.

You have to specify the MIME type of the script to the Webserver. In case of Apache, edit the file httpd.conf in the directory /etc/httpd/conf/and add a line at the end as below:

addtype application/x-ns-proxy-autoconfig .pac

Now in the Address text field of the browser type thefollowing URL:

http:// /script.pac

For more complex scripts check out

http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/proxy-live.html

Netscape Navigator

In case of Netscape Navigator, go toEdit>Preferences>Advanced>Proxies. Select Manual proxy configurationand then fill in the IP address and the port in the text fields for FTP, Gopher,HTTP, Security, and WAIS proxy.

Automatic configuration using a script is similar as abovewith an exception. If you are placing the file in the local filesystem of aLinux machine, say at /etc, then enter the URL as:

file:/etc/script.pac

Opera

Go to File>Preferences. In the Category list, selectConnections and then click the Proxy servers button. In the presented textfields enter the IP and port of the proxy.

Lynx: the text-only Linux browser

For Lynx, the text-only browser in Linux, edit /etc/profileand add the following lines, assuming that the IP address of the proxy server is192.168.1.1 and the port is 8000:

export http_proxy=http://192.168.1.1:8000/

export ftp_proxy=http://192.168.1.1:8000/

export https_proxy=http://192.168.1.1:8000/

export gopher_proxy=http://192.168.1.1:8000/

export wais_proxy=http://192.168.1.1:8000/

GetRight 4.1

Click on the GetRight icon on the taskbar and selectTools>GetRight Configuration. Select the Proxy tab and check Use proxyservers. In the http Proxy text field, fill in the IP or hostname of the proxyserver.

Windows Media Player 7

Go to Tools>Options and click the Network tab. Check theprotocols supported by the proxy server you are using. Then click the Configurebutton. Here, select either Auto detect proxy settings or select Use thefollowing proxy server. In the latter case, you must manually enter the IPaddress or hostname of the machine that runs the proxy server and the port usedby the proxy.

RealPlayer 7

Select View>Preferences and click on the Proxy tab. Clickthe Manually configure HTTP proxy radio button and in the text fields enter theIP address and port number. If you’ ve already configured your browser forusing the proxy, you can click the radio button Use my Web browser’s HTTPproxy, instead. Since RealPlayer has the option of connecting to the Proxy usingHTTP, it’ll be able to play streaming media.

Winamp 2.65

Winamp also has the option ofplaying streaming audio over the Inter-net. To configure the proxy, right clickon the Winamp player. Select Options>Preferences. In the tree structure onthe left, select Setup. From Internet Settings, select the Using LAN Internetconnection radio button. In the text field–HTTP proxy–enter the proxyconfiguration in the format:

:

For example :

192.168.1.1:8000

ICQ 2000a

Select ICQ>Preferences. Click the Server tab. Select UsingFirewall and then Using Proxy radio button. From the Proxy drop-down list selectfrom either
Socks 4, Socks 5 or HTTPS protocols, depending on which is supported by yourproxy. Then click the Firewall tab. Enter the IP address or hostname and theport of the proxy server in the Host and Port fields respectively. If your proxyserver requires authentication, then check Authentication and fill in theusername and the password.

You might have seen that all these applications have a moreor less a similar way of configuring the proxy server. So just in case we’vemissed out one of your favorite applications, you should still be able toconfigure it on the same lines.

Shekhar Govindarajan