web design and hosting
features and pricing my account customer support about ICG Link, Inc. contact ICG Link, Inc.

Script Errors - blocked referrers
Normal web site activity used widely on the Internet, including several of our scripts, relies on referers to verify where the visitor last came from. Some firewall programs such as Norton Internet Security (NIS), Norton Personal Firewall (NPF) or ZoneAlarm Pro 4 block referers by default. This is a problem, not only for some of our scripts but for many sites on the web. Referers pose little or no security risk or privacy threat. In fact, this action disables an important tool that web sites use to go about their daily business. We recommend that you disable this "feature."

How Referers Work

When you click a web page, your browser notes the current page that you are on and sends that information to the server of the new Web page. This way, the server for the new Web page knows the last Web page that you viewed.

For example, if you are on www.icglink.com/pagename.html and click a link that leads you to www.icglink.net, the browser sends www.icglink.net the information that you were just viewing www.icglink.com/pagename.html. If you block referer information, the server of the page you are requesting to see does not know what page you saw last and assumes you must have typed the URL in directly. If that is the case, the new page can't use the previous page information in any scripts or other features that might actually help you in your browsing.


If you want to allow referer information to pass to a particular web page in NIS or NPF, you must create a rule for it. Make sure that your rule is written for the web site that requests the information and not for the web site that would send out the information.

To create a rule
  1. Open NIS or NPF.
  2. Do one of the following.
    • In NIS/NPF 2002 and earlier, click Options > Internet Security or Personal Firewall (This step is not always needed), and then click Advanced Options and then the Web tab.
    • In NIS/NPF 2003, click Options > Internet Security or Personal Firewall (This step is not always needed), and then click the Web Content tab.
    • In NIS/NPF 2004, double-click Privacy Control, and then click Advanced.
  3. Click Add Site. A new site/domain box appears.
  4. Enter the name of the site that you want to receive the referer information and click OK. In this example, it will be www.symantec.com. The site name appears in the left frame of the Options window.
  5. Click the name of the new site.
    • In NIS/NPF 2002 and earlier click the Privacy Tab and check the "Use these rules for..." box and change the Referer from "Block" to "Permit." Click Apply, then OK.
    • In NIS/NPF 2003 and later, click the Global Settings tab, In the "Information about visited sites" section, clear "Use default settings," Click Permit.
  6. Click OK to close the Options window.

The referer switch in ZoneAlarm is also hard to find. First, open up the ZoneAlarm Control Center, and go to the Privacy tab. (That much makes sense.) Once there, you need to click on the Custom button in the Cookie Control section.

This brings up a dialog called Custom Privacy Settings, open to the Cookies tab. (In the previous window, you could have clicked one of the other two Custom buttons to also bring up this dialog, only you would be on one of the other tabs.) Then in the 3rd Party Cookies section, make sure the option "Remove Private Header information" is NOT selected.

Click the Apply button before you leave, and then click OK to leave this dialog. You can shut down the ZoneAlarm control center after that, and your changes will be saved.

(Thanks to Bruce Kratofil of BJK Research for the ZoneAlarm tip!)
ICG Link, Inc. 7003 Chadwick Drive, Suite 111, Brentwood, TN 37027