Issue: Redirecting sites using IIS settings for permanent redirect, results in infinite redirect loop when going through ISA. Accessing the sites internally (without ISA) results in the correct redirect operation. The web server has 3 sites configured for this for various reasons. One "real" site that is the actual web content and only accepts requests for specific headers. One redirect site that is configured for permanent redirect to the "real" site. The second site only accepts request for specific headers. The third site is also a redirect site but is using script to accomplish this. This site was the original site name, but the site has been moved to a different domain. The second site in this scenario is for variations of the "real" site which is why it's redirecting. None of the redirected web sites are working. They all result in a loop that eventually causes ISA to tell me that there have been too many requests from my IP address. (of course)
The IIS server is hosting multiple web sites, most with their own IP address. However, for this particular change, two sites have been configured with the same IP address, using host headers to control the traffic.
Since both external URL's point to the same internal server, the Firewall Policy is configured for the Public Names www.abcde.com, abcde.com, www.12345.com and 12345.com. The published site name is www.abcde.com. There is no authentication and all traffic is HTTP. "Forward the original host header..." is enabled.
ISA receives the requests and forwards the request to the IIS server.
The IIS server processes the request to the correct "redirect site" (B) which responds with a permanent redirect to www.abcde.com (A)
ISA receives the response (Here's where it gets good!) and inspects it, sees that there is a redirect link to the website that matches the configured internal site as configured in the Firewall Policy, it replaces the link with the original host header (www.12345.com) and forwards the response the the requesting user
The browser receives the redirect response so it goes to the "new" site, www.12345.com, and the process starts all over again
I was told that this was a "logic" issue (not a problem) that is not impacted by Link Translation settings. Seems that our specific configuration had just the right elements to cause this. The resolution was to replace the published site name (found on the To tab of the Firewall Policy) to the actual server name of the IIS server. Since the published site name no longer matched the redirect response, ISA no longer replaced the url contained in the response.
I hope this helps someone else if they ever need to configure redirects.