I like @0xC0000022L's "mode switch" idea. It seems like it should work for you, particularly for your testing.
There are at least a few ways to make this scheme work for the case where you are demonstrating it to other people.
- Build a webpage that you can visit and supply a list of one or more IPs or even ranges of IP's that treated in this special testing mode. An advantage for this in testing is that you can add additional customization actions to that page like setting various thresholds, reset various status, restarting various activities, clearing datasets, etc.
- Similarly, you could do the same by sending a specifically formatted email through the server with coded instructions to add remove IP's from the "demo" list or any number of other customizations and tweaks.
- Again, similarly, transfer a file (FTP) to the server to provide these coded instructions.
Of course all these features would be removed/disabled in the "production" version.
As far as your original question about changing your IP repeatedly:
For me, there are 2 ways I can get a new public IP Address.
If I power the router down for a minimum of 12 hours, when I turn the router back on, it gets a new IP Address. This of course is not a workable solution for what you want to do.
The other way... if I edit the MAC Address in my router, changing it to any "random" address, and then do a soft reset on the router, it gets a new IP Address. A complication with this is that there could be a problem (most likely would be a problem), if the "random" MAC Address you choose duplicates an existing MAC Address on the network, there could be a conflict that prevents connectivity.
Also, depending on how frequently you want to change your IP Address, and over what period of time you want to make those changes, there are 2 other issues:
- If you change the MAC address back to a previously used MAC Address too soon (for me it's 12 hours), you will get back the previous IP Address as well.
- The IP Address that is given to the router is assigned from a pool of IP Addresses. It is not unlimited, or even likely to be a very large number, and may even be a relative "handful" of possible IP Addresses that could be assigned to the router before they begin to be reused.