This is done by inserting the line:
before the existing line
in the apache httpd.conf file.
On windows, this is located at "C:\Program Files\Novell\apache\conf\httpd.conf"
Be sure to use the same max header size in Apache (AG) and Tomcat (IDP) and don't pick a larger value than absoluetly necessary to ensure that overall performance is not adversely impacted by this adjustment.