I have installed the DNN Platform 8.0.4.226 using the default IIS settings on the default port 80. But the server is on a virtual machine, so for the outside world the 80 port is accessible through the redirected port 5581. The systems works fine when I connect to the machine using remote desktop connection and I access it using localhost. When users try to access it remotely using http://jerry:5581/dotnetnuke/ the page opens correctly, but all links at that page (including administration toolbar at the top) miss the port number, so they look like http://jerry/dotnetnuke/host/host-settings/portalid/0/Admin/User-Accounts and of course they don't work.

Is it a configuration problem or the platform doesn't support that setup at all? How can I fix it?

We have hundreds of virtual machines. Many of them are accessible through a public IP. We would need hundreds of public IP addresses if we couldn't use port redirecting.
And the application should use relative URLs not to override any part of it (protocol, host name, port number).