No Wake-on-LAN possible since updating to ML

Thanks Alfred. The system prefs are alright and, of course, set to "Wake for Ethernet Network Access" is enabled. Furthermore, several programs and tasks are running in the backgound (Cubby, LogMeIn, hourly Time Capsule backup), but none of them brings the Mac back from sleep. Basically, the Bonjour Sleep Proxy should maintain the network connection to the sleeping Mac, but it's not working anymore. Even a direct afp connection to the sleeping Mac mini from within the local network fails. After it went to sleep, it disappears from the network.

Yes, wired. It's a wired Ethernet-over-Power Line connection, see www.devolo.com for technical details. WiFi is turned off. Anyway, wired and WiFi use the same static IP address within the LAN, it's alway 10.0.1.2, the standard host for NAT port forwarding. The network setup has always been this way and never caused problems. It has been running smoothly for almost 18 months now, using LogMeIn, Plex, jDownloader, EyeTV and other stuff for remote access via iPhone, iPad or web interfaces. Glitches started after upgrading to ML.

I just had the idea that the DHCP lease time configured in the Time Capsule might be the source of the problem. It was set to three hours, which explains why the Mac mini (10.0.1.2) eventually disappears from the list of network devices after it went to sleep: IIRC the Bonjour Sleep Proxy discards the IP reservation as soon as the lease time has elapsed, making the corresponding network device unreachable. Well, I cannot remember I changed anything in the network setting of the Time Capsule, but increased DHCP lease time to 60 days now. As soon as I get home, I will push the Mac mini's power button to re-register it's IP in the LAN and check if the new DHCP lease time solves the Wake-on-LAN issue.

I wonder why I did not run into that problem with Snow Leopard or Lion. Maybe they really changed something under the hood with regards to the Power Nap feature. For now, it's just guessing, so any further ideas are warmly welcome.

Thanks Alfred, I will check the link you provided (I missed that one) and reset SMC and PRAM when I return home this afternoon.

You're absolutely right, one should rule out every possible cause for error. I will try a direct connection if the DHCP lease time does not solve the problem, but I doubt that the dLAN adapters have anything to do with the issue. Network traffic is running perfectly well.

Ok, I did not expect that, but it really seems to be connected to the dLAN adapters. They go to sleep as well, a few minutes after the mini did. That's why the connection breaks. I never had that behaviour with SL and Lion, but it seems to be the way it should have worked from the beginning.

I tried a direct connection between mini and Time Capsule and it worked perfectly well, at least a few minutes after putting the mini to sleep. I did not try a longer period of time as I have no possibilty to connect the mini directly to the router. My workaround will be disabling sleep mode until I find a solution.

Randall, problemss,

how do you connect your computer to the internet? Wired directly, wired with dLAN or WiFi?

I don't think that it will help much, but you can try. As long as you're using a router that's offering the Bonjour Sleep Proxy service, using WiFi instead of wired connection may improve the situation.