Apple TV Not Waking on Demand for Computer Behind Switch

appletvhome-sharingNetworksleep-wakewake-on-lan

I can Home Share between a Mac Mini, Mac Pro, and my AppleTV with no problems as long as the two computers are awake. The ATV finds and streams the libraries with no problems.

The Mac Mini and ATV are connected to a switch, while the Mac Pro is connected directly to the router. Everything is on the same subnet and has the same IP range, and everything is wired (not using Wi-Fi).

If the Mac Pro is asleep, the ATV seems to be able to wake it on demand and stream it's library (after I added specific port forwarding rules to my router as suggested by Apple – details below). Again, the Mac Pro is connected directly to the router.

The main problem is with the Mac Mini, which, along with the ATV, is connected via a switch. If that computer is asleep, it will not wake up and the ATV can not stream it's library.

One weird thing I've noticed is that if both computers are awake, the ATV shows both libraries as available to stream. If I sleep everything (including the ATV) then wake it up, both computers appear as available to stream, but when I click in to the Mini's library it fails to load.

Also, the last time I checked, Wake on Demand was working over Wi-Fi, but I'd prefer to keep as many devices hard wired.

About My Setup:

  • Router:

    • IP Address in the range of 192.150.23.xxx
    • Subnet on 255.255.255.128 (This was done in order to port forward to the broadcast IP address. On a standard subnet of 255.255.255.0, my router wouldn’t let me forward to 255.255.255.255. I read that I could change the subnet to 255.255.255.128 and broadcast to 255.255.255.127.
    • Port forwarding: everywhere I read on the web recommended forwarding port 7 over UDP to my broadcast IP address of 192.150.23.127. After speaking with Apple, they also recommending doing the same with ports 1900, 5350, 5351, and 5353.
    • I verified this subnet change and port forwarding is working as expected because I downloaded an iPhone app called mWOL and it can send a magic packet and wake any computer I point it to.

  • Mac Mini:

    • Wired connection to switch
    • Energy Saver > Wake for network access checked
    • iTunes open

  • Mac Pro:

    • Wired connection to router
    • Energy Saver > Wake for network access checked
    • iTunes open

  • AppleTV:

    • Wired connection to switch

Any ideas what could be happening? Could the magic packet be getting swallowed when sent to the Mini? Perhaps related to the fact that I’m using a switch?

Best Answer

I would think that the magic packet is indeed getting "swallowed" by the switch.

I suspect that the UDP broadcast packet containing the WOL magic packet is going through the switch from the ATV while the Mini is switched out. Could you replace it with a hub or router for a time to test? UDP broadcast is always fun.

Can you wake the Mini from the Pro?

If you can then that tells us that WOL is working on the Pro and the problem is indeed the switch. You need to configure the switch so that it somehow holds and rebroadcasts the UDP broadcast packet on all ports.

The problem is that the ATV and Mini are on the same switch.

What is the brand and model of the switch?

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