When you use a Site and Content rule that allows you to gain access to a selected destination set, if that destination set contains both a domain name and an Internet Protocol (IP) address, you can gain access to either that domain name or that IP address.
However, when you create a Site and Content Allow rule, and then create a Site and Content Deny rule that denies access to all destinations except a selected set, if you specify the destination set that is used in the Site and Content Allow rule, you are denied access to either the domain or the IP address that you specified in the Site and Content Allow rule. In addition, you may receive the following error message in your Web browser:
HTTP 502 Proxy Error - The ISA Server denies the specified Uniform Resource Locator (URL).
(12202) Internet Security and Acceleration Server
If you create a Site and Content Deny rule that contains a redirect action for Hypertext Transfer Protocol (HTTP) requests, you do not receive the preceding error message. Instead, you are redirected to the custom deny page.