All Barracuda SSL VPN products firmware 1.3 and earlier.
?Wake on LAN? (WoL) requires the network hardware (MAC) address of the destination computer. The Barracuda SSL VPN automatically detects the MAC addresses of local machines by looking at the SSL VPN's local ARP cache. However ARP is a broadcast-only protocol, meaning ARP packets only reach within the local subnet.
If the SSL VPN is installed in a DMZ environment, most WoL resources will likely to be on another subnet, and beyond the SSL VPN?s ability to determine the MAC address of the requested WoL resource.
The WoL protocol itself also does not route across subnets, so even if MAC addresses are manually entered, WoL resources outside the local subnet will still not receive WoL packets.
Link to this page: