Is Dynamic IP a problem?

[Гость urubi]

Hi,
I'm very interested in buying RBTools and I need to insert my IP. The question is: my IP can't be static, it's just dynamic. 

The first numbers most likely will never change since it's the same provider and I'll use from the same office, in the same city, always. Also, this is a local provider which can be found only in this specific city. However, my IP changes every time I reset the modem or when something out of the curve happens, such as a power surge. The IP could change every 15 days or so.

Is that a problem? What would be the best course of action about licensing the software?
(Yup, this post can be answered in Russian if you prefer)