So I've had an interesting issue that I think I know what might have happened, but I'm not sure if it is actually possible. I have 2 Mac's running High Sierra, Laptop and iMac. I have enabled "Wake for Network Access" to facilitate waking the system up for Back to My Mac or some such. Now, my iMac is almost never actually in sleep mode (being a desktop, I don't have it configured to automatically sleep).
Here is what happened, there is a software package I have that has a bug, and automatically tries to reconnect to a voice chat that is over if it's been asleep for over and hour and wakes up. It is in the works to be fixed, but has not been fixed yet (confirmed this with the developers).
Now, 3 times in the middle of the night while I was asleep this behavior occurred. I confirmed that my sleep monitor says I was asleep at the times in question. Since I live alive, I'm not sure why or how the system would have been woken up from sleep. The iMac was not asleep, but the MacBook was; and not on a wired connection. I have a VPN provided by ZeroTier One (not a standard VPN as provided with OpenVPN protocols, LT2P or PPTP).
So here is my basic question... Given that the iMac was awake, could it have received a broadcast packet from the VPN on ZeroTier, from a distant system connected via the VPN / Internet that unintentionally woke up my Laptop? How would I find out if the Laptop woke up and what system triggered the wake up? I have been looking and according to what I read, the computer won't know who or why it was triggered to wake up (unless I read it wrong). My understanding of the "sleep proxy" of Bonjour is that a running system on the LAN could be used to trigger a system on the LAN to wake up based on a signal from a system on the VPN -- again, I could be horribly misunderstanding the protocol.
In short, how would I found out if this happened / is it even possible?