OK I've seen this enough times now to think it might be a bug.
While moving a site from one server to another I.

Zipped the DNN folder
Backed up the database
Unzip Folder on new server
Restored the Database
Changed the webconfig connection string.
Setup the Virtual Directory.

Lanch site using Server IP address (this is the important part watch the Urls)
http://123.123.123.123
Portal Alias Sends me back to the original server.

Add the IP address to the portal alias table
Lanch site using Server IP address (this is the important part watch the Urls)
http://123.123.123.123
wait an half hour while the browser niether times out nor connects

Reboot Server (ok overkill but wanted to prove a point).
Lanch site using Server IP address (this is the important part watch the Urls).
http://123.123.123.123
Still no joy

Lanch site using Server IP address FOLLOWED BY A "/"(this is the important part watch the Urls).
http://123.123.123.123/
The world is good all is fine site loads.

Once is a fluke. Twice is suspect but this is the third time. On the third different site (Moving my clients off of Godaddy Shared Hosting thier support is hideous).

One note after I go to http://123.123.123.123/and it loads the first time. http://123.123.123.123 works fine from then on.

 Anyone else notice this?

Looks like I have the same issue, but the workaround doesn't work for me :(

I've setup the site as first poster mentioned - the difference that I stay on same physical server, but different domain name (e.g. changed domain name). Old name is not avalable now - it was a random generated subdomain name, so I have to find out how to do this manually.

I went to PortalAliases table and changed the value (only one record there) to the new domain name, in form www.domain.com. The problem now though that I keep being redirected over and over, kind of loop. Adding slash at the end didn't solve the problem :(

Yes, same problem happened to me just an hour ago.

I have copied all files from old host to new one, restored database, modified connection strings, edited portal alias to "localhost" and created new web site in IIS.
Typed localhost in internet explorer and hit enter waited 5 minutes but nothing happened.
I thought i could find a solution in this forum and saw this post, tried http://localhost/ with the "/" at the end like David wrote, and site showed up...

I think it is the exact problem happened to David.

by the way, my dnn version is 4.7.0