Is it possible to WOL via OpenVPN?
Yes it is.
Is there any way I can power on the PCs when tunnelling through OpenVPN?
Yes, you've got following options:
- use OpenVPN in bridge mode (VPN & LAN share layer 2 segment, TAP device),
- forward UDP port 9 at your router from VPN side (when using VPN layer 3 subnet with TUN device),
- forward UDP port 9 at your router form Internet side.
Configuring router port forwarding:
Most routers do not allow you to forward to broadcast, however if you
can get shell access to your router (through telnet, ssh, serial
cable, etc) you can implement this workaround:
$ ip neighbor add 192.168.1.254 lladdr FF:FF:FF:FF:FF:FF dev net0
Enabling Wake On Lan on the network adapter (Linux way):
ethtool -s eth0 wol g
Enable WOL via /etc/networks/interfaces (Debian, Ubuntu, Mint probably too):
$ cat /etc/network/interfaces.d/eth0
iface eth0 inet dhcp
wol -p forwarded_port -i router_IP target_MAC_address
wakeonlan -i 10.0.0.255 FF:00:00:00:00:30