Thanks for the comments. Are you sure your method works after, say, 4-6 hours of the target PC being shutdown / asleep? I have a similar setup as you described (though don’t use dyndns – don’t think that would change the equation). WOL works for me over BOTH LAN and thru the internet with my setup. However, after a few hours of PC being shut down, WOL over internet stops working (still works over LAN using a broadcast address). From perusing other forums, the explanation was that the “ARP cache” of the Time Capsule clears itself every few hours and therefore loses the target PC’s IP address – so can no longer forward the magic packet to the right spot. In addition, the TC is apparently unable to transmit internet traffic to a broadcast address which would work (not sure what imposes this limitation).

So, possible “fixes”:
1. Ways to change the “ARP cache” timeout duration so it doesn’t clear as often?
2. Ways to hack the Time Capsule to make it broadcast to entire network from over the internet? (Read elsewhere attempts at this using subnets, with no luck)
3. I know very little about Bonjour Sleep Proxy (Mac’s Wake on Demand) – maybe this could be part of the solution?

1. Get an DYNDNS account and receive your current router IP address via DYNDNS
2. Give your local Mac Machine a static IP address and also configure it in Airport Utility
3. Configure Port Forwarding in Airport Utility both for UDP and TCP. I did it for port 9 (Wake on Lan), 5900 (VNC), 5109 (iStat), 9969 (StreamToMe), 5902 (Remote Tap)

4. In your remote tools (iNet WOL, Mocha VNC, iStat, StreamToMe, Remote Tap) configure the DYNDNS address for accessing your machine over the internet.

This works. In my testing I made the experience that Port 9 was not sufficient.

So this topic is more than a year old now – has anyone found any workarounds? I am in the same situation as many of you (using a Time Capsule): WOL works perfectly when on the local network all the time, but WOL over the internet works for only an hour or two after the PC has been shut down/sleep. Tried the proposed solutions offered here and elsewhere: 1. making DHCP lease a very long time in hopes of the TC “remembering” the IP for longer, 2. creating static machine-assigned IP outside of DHCP block, 3. trying to have port forwarding send the magic packet to a broadcast address instead of the machine address (x.x.x.255). Nothing works so far. Seems like the functionality for #3 could be easily addressed in a firmware update, but I am running the latest (7.5.2) and it doesn’t work for me. Brett’s solution sounds like a sloppy but functional workaround – but not for me since my PC is right next to my bed… So – any other creative ideas out there?