WoL - based on incoming traffic request

  • In this day of everyone thinking "green" and all, I was tasked at a clients office with trying to reduce the power usage of their network gear.  I've been working in BIOS/scheduled rtc wakeup commands to automatically start up the required servers in the morning, and shut them down at end of day, and then bring them up for scheduled overnight backup jobs, etc.

    This got me thinking though, there are many use cases I have seen (could be just me though!) on both home and small(very small) office networks that a port-knock-triggered WoL packet might come in handy for.  I'd try to write something but I'm not too sure where to start.  Figured I'd throw this out there in case anyone has any general ideas that might get me on the right track.

    Case 1:  Home user, mythtv or other media server.  Low traffic, can easily be scheduled with rtc and BIOS/ACPI commands to wake up based on any schedule.  However, this server is also accessed externally, say for an unscheduled media download, or other unscheduled access, say to a saved document that is needed, a backup file remotely, etc.  Being able to just make an ssh connect attempt to that IP could trigger a WoL packet - that way if the server was not already up, it would begin booting, and the user could just retry in say 5 minutes and have access.

    Case 2:  Small office user, similar situation.  I think this would be mostly useful for devs or tech troubleshooting after hours, or possibly even an extremely-low-traffic internal site that does not have to be up all the time – internal users would know that it would take a couple minutes after an attempt to access it for it to come up.

    SO - rant away, believe me I know pfsense is a serious firewall distro, and I would not suggest anything that would compromise it - I merely had a thought and figured I'd share, see if anyone else thought it might be useful.

    Thanks for the time!