Tonight, I discovered I had left something on my Mac at work that I wanted at home. The problem: my machine at work is sleeping, like most of the personal machines on our internal network when we are not in the office. It is also wirelessly connected to our internal network, not connected via ethernet (for those one step ahead of where this post is going).
However, my machine at the office is also set up for Wireless Wake on Demand. Those who are interested can read some technical details here and setup details here. This is new in Snow Leopard, and you might recognise that we are talking about waking a machine that is wirelessly connected to a network, not a simple Wake-On-Lan sending a magic packet over ethernet.
So I VPNed to work from home, went to my Finder, selected the menu
Go->Connect to Server... and put in “
jamie.internal” (my machine’s name on the office network). My machine at work was woken in the background, and I connected to the machine as per normal in the Finder, got the file I wanted, disconnected, and closed down the VPN. My machine at the office went back to sleep and I had the file I wanted.
I could also have shared the screen to manipulate my Mac via its user interface, and apparently even shared iTunes if I had it running.
There is a bit more going on here than just sending a magic packet wirelessly to wake the machine – the Mac is asleep, but our office wireless router is broadcasting over bonjour the services my Mac can actually handle as if it was awake on the network, so that if I try to use these services, it wakes the machine up first. This also means then that my machine in the office, even when sleeping, will still appear on other machines on the internal network as if it was awake, advertising all it’s services. Similarly, if I had it sharing music in iTunes, it would appear as a shared source of music on another machine in iTunes, even when asleep.
This is obviously a very handy feature – possibly more so for my colleagues than for me given I could walk over to the office in 10 minutes from my home to manually get the file (though it is after midnight, and Melbourne streets at night are a little dangerous these days, so I possibly avoided a random stabbing or glassing).
I’m sure you can also see advantages in a system like this for the environment too – machines don’t have to necessarily be running 24 hours a day just so you can access an occasional resource.
This will also work for Macs connected via ethernet. It may also work from a Windows machine to access a Mac at your office (with a SMB share). Not tested, as Windows is not welcome in my home, but I assume it will work.