Access to iStore and other product pages from outside the DMZ server is controlled by entries in
$IAS_ORACLE_HOME/Apache/Apache/conf/url_fw.conf file. This file lists all the pages to which access is allowed from DMZ server.
You need to put the following line in the INITIAL section of url_fw.conf:
RewriteRule ^/$ /OA_HTML/ibeCZzpHome.jsp [R,L]
As mentioned in Metalink Note 459501.1(How To Allow Access To Custom Istore JSP's From DMZ Server), to enable access to custom istore JSP's whose name does not start with ibe*, url_fw.conf file need to be updated. For example, If custom jsp's follow the naming convention of ABCibe*.jsp, need to add an entry such as this in url_fw.conf file.
#RewriteRule ^/OA_HTML/ABCibe.*\.jsp$ - [L]