Can I get my Mac to wake from sleep for an SSH connection?

I use Infuse on my iPad to play videos stored on my Mac. However, after a few tens of minutes, the connection drops, and it doesn't reconnect. Restarting Infuse doesn't help. When I walk over to the computer, the hard disc light (it's an external disk) is off. When I move the mouse, the hard disc light comes on, and Infuse starts working again. I tried unticking "Put hard discs to sleep when possible" and it made no difference. I tried resetting NVRAM and SMC and that didn't work either. I now ticked "Prevent computer from sleeping automatically when the display is off". Inufse now works reliably, but I don't like that the Mac is wasting energy, and possibly shortening the life of its components. Configuration: - iMac 5K (Late 2015), running 10.12.4, connected via Wifi - Infuse Pro 5.4 on iPad 13-inch running iOS 10.3.1 - The connection is via SSH. **How do I let my Mac go to sleep but wake up when Infuse connects via SSH?**