If you are getting a DotNetNuke redirect loop upon deploying your site to a production web server it is usually one of two things:
1) You are setting the trust level to medium and using the 1.0.61025.0 version of System.Web.Extensions. Update the trust level to full and and update ALL occurrences of System.Web.Extensions to 3.5.0.0 in the web.config (assuming .NET 3.5 framework is installed).
Original:
<trust level="Medium"...
...
...System.Web.Extensions, Version=1.0.61025.0...
Updated:
<trust level="Full"...
...
...System.Web.Extensions, Version=3.5.0.0...
2) You have a trailing slash in the HTTPAlias field in the PortAlias table, remove it.
That’s it