Creating Custom HTML Error Messages to Be Returned to Clients

This article describes the Microsoft Internet Security and Acceleration (ISA) Server error messages that are returned to Web browser clients, and describes how to create custom Hypertext Markup Language (HTML) error messages.

ISA Server distinguishes between external and internal client requests. For internal clients, the files are named Error_number.htm. For external clients, the files are named Error_numberR.htm, where "R" indicates reverse.

The following list describes the error files that are returned by ISA Server:

• File name: 10060.htm and 10060R.htm
  Description: The specified Web server could not be contacted.
• File name: 11001.htm and 11001R.htm
  Description: The specified host could not be found.
• File name: 11002.htm and 11002R.htm
  Description: The DNS name server for the specified host could not be contacted.
• File name: 11004.htm and 11004R.htm
  Description: Host was not found.

Custom HTML Error Messages

You can create additional Hypertext Transfer Protocol (HTTP) error messages that are customized for your organization. You can use the default HTML error files as a basis for creating additional HTML error message pages. The files should be named "Default.htm" for internal client errors and "DefaultR.htm" for external client errors and should be located in the \ErrorHtmls folder. Error message pages are named Errorcode.htm.

You can edit the Default.htm file in the same way that you would edit any HTML page. To do this, use the following method:

• Replace ERRORNUM with the HTTP1.1 status code, as described in RFC 2616.
• Replace ERRORTEXT with the appropriate error message text.
• Replace SERVERNAME with the name of the server that returns the HTML page.
• Replace VIAHEADER with the Via header message string that the ISA Server-based computer receives.

You can use inline graphics that are in the form of .gif or .jpg files in your custom HTML error messages. However, these files must be stored in a separate, shared directory on the computer that is running ISA Server. Fully qualified URLs that point to inline graphics must be used in the HTML error message files.