Not 100% sure that will work, using UDT that is. UDT is geared towards learning client IP addresses that are connected to switchports. So I can see a couple problems there, first you would need to manage all your router ports, then it would have to discover the IP of the router itself, not a client connected to the port. Not sure it does that, but typically I don't manage anything but switchports in UDT, so its possible it might.
I'm also thinking that UDT doesn't look for IP address conflicts across your whole network, but instead looks for them within each distinct network.
These pages below explain the process that UDT uses and I think it backs me up in this... However, you never know, it might work. I wouldn't purchase it with the intent of this working, but if someone has it it might be a neat experiment. UDT has never picked up on anything that the queries I wrote have picked up on though.