I finally have restored connection to my lab. It was exactly as I had thought, the VPN VM was configured to collect it’s address via DHCP but the DHCP server had hung at startup. My VPN server now is assigned a static address so I don’t have to worry about the hangups anymore. To be totally sure I went ahead and simulated a power outage (because they are very frequent where I live and that was the problem in the first place) and sure enough the VPN server was running even with the DHCP server still powered down.

This was a bit of a rough lesson, but a good one for sure. Friends don’t let friends use DHCP for critical services!