Routed network WoL support

[MrTux007]

Hi

Feature request of routed network WoL support.

At the moment only device on the directly connected network (broadcast domain) can be waked up. This is because the magic packet is sent as broadcast. To wake up device on routed networks, the magic packet needs to be sent to the IP address of the device (unicast).

Requirement on the destination network: for the device to wake up there need to be a static arp entry in the destination router.

Would be great if this feature could be implemented.

thank for this great tool.

[MrTux007]

Hi

Any feedback if this request could be implemented would be great. If I can help, let me know.
Maybe the easiest way would be to send 2 packets, one broadcast and one unicast.

thanks

[seriousm4x]

Thanks for bringing this up. Unfortunately, I don’t have much knowledge in this area of networking, and I also have very limited options to test it at home.
Is it just a matter of sending the WOL packet to the exact IP, or is there more to it? I’ll need to read up on that.

[MrTux007]

yes, just send it to the unicast IP address of the device. the only requirement is, that the mac address is known in the destination network (in the ARP table). Normally, arp entries of offline devices will be deleted after some time, to prevent this, the arp entry should be defined as static/permanent at the destination router.
In my environment (several networks connected together with VPN's) it's working fine, normally I send a magic packet with a wol binary, but I also tested it with the UpSnap docker image. I installed the awake package and used the "Custom wake command" of UpSnap.
If you need a tcpdump of broadcast and unicast packet, or a test environment, or any information where I can help, let me know.

[invario]

@seriousm4x If interested, I can modify your wakeUDP function to take one more parameter (device IP address) and it will send two more wake packets for this (for a total of 6 packets). Should be pretty straightforward. The wol package does accept IP addresses.

[seriousm4x]

@invario Sure, always looking for help :)

[invario]

I have the changes made in and can push the PR. I know the changes I made didn't break existing functionality but I'd like to get things setup in my network to test the functionality. I need to put a WOL capable device on a different subnet to see if it works.

[invario]

PR #1620 submitted. I tested it on my local setup using two subnets and a router with static ARP entry. On my test setup, I temporarily isolated the unicast code to ensure it was in fact the unicast packet waking the computer up on the other subnet, and it succeeded. (6) total packets will be sent now in an attempt to wake a computer up: 4 broadcast, 2 unicast.

[seriousm4x]

@invario Thanks!

@MrTux007 can you test if this is working for you with 5.3.2-beta.0?

[MrTux007]

tested with 2 remote devices on 2 different networks (over VPN), working perfectly.
also tested local devices, still working :-)