Creating a Customized Error Page - Updated Jan. 16, 2003

Jan. 16, 2003 - Thanks to Incognito from the Novell Public Forums for this information on Internet Explorer. He was having problems getting his custom error page working when he found out this bit of information:

"I found the following information, added a bunch of whitespace to the pxyerr.htm error page to make it larger, restarted the proxy and voila .. it now works ..

The recently released version 5 of Microsoft's Internet Explorer has some new "features" which may affect sites.

The first new "feature" is that MSIE 5 may replace a site's own error messages with its in-built error pages. This occurs if the error page from the site is less than a particular size.

For most errors, this is 512 bytes. If the error page from the site is more than 512 bytes, MSIE 5 will display the site's error message, otherwise it will not display it.

For a few statuses (403, 405 and 410), the cut-off size is 256. The solution to this problem is to ensure that all error pages are greater than 512 bytes.

However note that most of Apache's built in error messages will be less than 512 bytes, so the only way to ensure that viewers see the site's real error pages is to use the ErrorDocument directive in Apache."

Dec. 18, 2001 - Thanks to Holger Schaekel for providing samples in German HERE. Instructions in English and German are contained in the included liesmich.txt files within the ZIP file at the link.

You can modify the default error page that BorderManager puts up. First of all, go to support.novell.com and get familar with TID 10018668.

That TID explains the syntax for calling out the variable proxy error codes, and it gives some ideas on how to create a customize error page. I pass on the following method, with credit given to Art Montoya of the City of Chandler for some of the important ideas here. Art thought that simply calling out the error code variable as the name of a GIF file might be handy, and it was a good idea. This technique allows you to easily put in whatever description you want for the error code by making a GIF file with the appropriate name. So, rather than have "403 Forbidden" show up as an error when someone tries to access an X-rated site blocked by CyberPatrol, you can instead show:

403 Forbidden - You have attempted to access an unauthorized site. All such attempts are logged, and the logs are made available for managerial review. You could be subject to dismissal. Contact the systems administrator at 555-1234 and offer him/her a hefty bribe to tell management that you were testing CyberPatrol for him."

There is one little problem that Art found in using this method. It worked great for Netscape, but it would not work for Internet Explorer. In Netscape, the GIF file called out for a 403 error worked fine as long as the name of the file was "403 forbidden.gif". IE just choked on it. Art found out that IE didn't like the spaces in the file name and needed to substitute a %20 variable. So, for IE, the name became "403%20forbidden.gif".

By duplicating every GIF file with spaces and %20 in the names, both IE and Netscape would pull up the proper graphic.

I have included a sample PXYERR.HTML file and many of the 400- and 500-level Proxy error messages in GIF file format in the link HERE(Zip format). Unzip the data, edit the file as desired, edit the GIF files as desired (create your own), and save everything to the SYS:ETC\PROXY\DATA directory. Reload PROXY.NLM to pull up the new custom error page.

Note: If you are having problems getting the proxy to use a custom error page, have a look in the sys:etc\proxy\proxy.cfg file.

It should have the following settings:

[MiniWeb Server]
Port-Number=1959
Root-Directory=SYS:\ETC\PROXY\DATA

If your root-directory is not the same as above, you will need to change either the root-directory, or the location of the custom error page files.

Note 1: The source address for the GIF files is called out as <PROXY_ADDRESS>/data/bmtext.gif (or whatever the filename happens to be). Some editors may cut off the directory part of the file name (leaving just bmtext.gif for instance), and that will not work.

Note 2: In my sample PXYERR.HTM, I call out a width of 444 for <ERROR STATUS>.gif. Be careful not to make your GIF files too large!

(By the way, I used Paint to create the 403 forbidden.GIF file, though I used Viewprint to crop it down as it was too large initially.)

I look forward to hearing feedback on this method in the Novell support forums. If you have a nice (simple) improvement to the samples, I'll be happy to try to incorporate it.

Download sample file HERE.

Note: Novell also has another way to do this. Look for the BMSAMP1.EXE file the Novell web site using http://support.novell.com/servlet/filefinder.


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