There is a way to allow a router to forward Layer 2 broadcast across a WAN?
For example, the feature "wake-on lan" used on some ethernet NIC, can be deployed also across a wan?
For WOL the work over the WAN, you need to first configure this command on the router connected to the server sending the WOL magic packet:
And on the specific interface connected to the WOL server:
for instance the directed broadcast address would be 192.168.2.255 if the subnet address is 192.168.2.0/24.
You also need to configure the interface connected to subnet where the workstations to be awaken reside as follow:
note that the ACL is optional but it is recommended to configure it so that just wake on lan packet sourced from the specific server(s) are forwarded. This will make sure that you don't open the door to Smurf attacks, which is the reason "ip directed-broadcast" is disabled by default.
Hope this helps,