#Mac wake on lan utility mac

WOL across the Internet isn't so (someMac,, wakeCallback)

Since you likely don't have a public subnet behind your router, but rather are using NAT to share a single public IP address on your LAN, there's no way to remotely address a packet to the subnet-broadcast address of your LAN subnet such that the router (if it could forward directed broadcasts) would generate a layer 2 broadcast with the WOL packet to allow the WOL client to 'see' it. You will need a router with static ARP capability to make this work.

#Mac wake on lan utility mac

When your router receives an IP packet port-forwarded to the WOL client's IP address while the WOL client is powered-off and its MAC address is aged out of the ARP table the router will not be able to deliver the packet to the client. You have a problem with unicast WOL requests from the Internet as follows: The MAC address of your WOL client computer won't be in the router's ARP table because, as the WOL client is powered-off, such an ARP entry would have aged out. You're on the right track w/ port-forwarding a UDP port from the Internet to the LAN, but there are other concerns. Sending WOL requests from the Internet is more problematic. Get a utility to make magic packets (like mc-wol for Windows) and fire away. The magic packet byte sequence just needs to be in the payload of a packet that the NIC to be woken-up will receive. The magic packet can be encapsulated in any type of transport (UDP over IP, IPX, etc). The WOL behavior in a client is triggered by a 'magic packet'. Some additional reading about Ethernet, ARP, and UDP/IP is probably in order, too. It sounds like some reading-up on WOL is probably in order first. The technique I've outlined will work for any computer on the LAN the way WOL was designed but could potentially open your network up to be used for as an attack (Smurf/Fraggle/Papasmurf) amplifier if someone were to send a specially crafted packet to the WOL port.Д®van Anderson's approach is technically more secure but is limited to unicast. This solution will work but it's only a hack to circumvent the limitations of the Wake On Lan protocol. Broadcasting incoming packets on a LAN is generally a bad idea. Update: Anderson made a good point that I forgot to mention. If there is sufficient demand, I could extend my console application to include packet sending (it currently only sniffs) and make it available as an OSS project. Note: The reason I know so much about this is because I'm the author of the WOL parser for SharpPcap (pcap wrapper in C#). There are tools online that can do such a thing but I'm not familiar with them. If you want to test that the packets coming across are in the right format, use the following filter in Wireshark: ether dst FF:FF:FF:FF:FF:FF and ether proto 0x0842Д«asically, the WOL application needs to be capable of creating a packet that spoofs the Ethernet Destination address. The frame structure is as follows: DA -> SA -> Type -> Magic Packet The contents of the magic packet contain 16 copies of the MAC address of the computer being woken up. To get around this limitation, they broadcast (ethernet broadcast not IP broadcast) to all the computers on the network and each computer reads the magic packet to see if they're the one being called on. They're blind to any protocol above the link layer. WOL packets were only really intended to be sent across a local network. So, where does the MAC of the computer being woken up go? The ethernet type of the packet should be 0x0842 (Wake On Lan). The Destination MAC address of the packet should be set to ethernet broadcast or FF:FF:FF:FF:FF:FF. To get the WOL packet into the network, forward the packet coming from a specific port to the broadcast address of the local network (255.255.255.255) or whatever subnet range you want WOL access to be enabled on.