Helping people with computers... one answer at a time.
I have a friend in Ukraine who uses gotomypc.com for remote access to work on my computer here in California. Gotomypc records the IP address of each computer when connected. Is it possible that her connection would cause several different IP addresses to appear in gotomypc, even though she is operating from one computer and one connection? Or is that impossible and that different IP addresses definitely mean different computers?
I hate when I have to say this:
It depends on several things, but most importantly how your Ukrainian friend is connected to the internet.
If your friend has been assigned a static IP address by her ISP, then I would expect to see only that IP address when she connects.
That's pretty simple, and unfortunately, probably the least likely scenario.
What's more likely is that she has what's called a "dynamic" IP address. That means that her ISP will automatically assign an IP address to her computer each time she connects to the internet. That IP address could be the same from one time to the next, or it could be quite different.
Even if she stays connected continuously, if she's getting a dynamic IP address, it can still change. Typically that's very infrequent, but it's completely at the whim of her ISP's networking equipment.
So is there anything you can tell about the situation?
I'd look at two things: how often you're seeing a different IP address, and how close (numerically) those IP addresses are to each other.
Say your friend connects to the internet once a day, and stays connected for several hours. It's likely, then, that you should see one IP address each day, though it might be different from day to day. If she connects and disconnects 10 times a day? Then you might see 10 different IP addresses. If she stays connected continuously, then I'd personally expect it to change no more than once a day. It could change more often, but I believe that would be rare.
Regardless of how often the IP address changed, it'd be interesting also to see if the IP addresses "relate" to one another. For example aaa.bbb.ccc.1 and aaa.bbb.ccc.2 - addresses that differ only in the lowest number - are likely to be from the same ISP. On the other hand, IP addresses that differ in the first number - 1.xxx.yyy.zzz and 2.xxx.yyy.zzz for example - rarely come from the same provider.
If the timing of the accesses matches your friends access, one additional concrete step you can take is to visit the ARIN (American Registry for Internet Numbers) "whois" lookup (whois.arin.net) to look up the ISP that owns each specific IP address you're seeing. If they all belong to the same ISP, then I'd be more confident that the accesses are probably from the same computer. Certainly if they do not come from the same ISP, I'd start to get concerned.