DIY Home Power Monitoring Solution – Perfect for Sandy

Intro
My recent experience losing power thanks to Sandy has gotten me thinking. How can I know when my power’s on? Or what if it gets shut off again, which by the way actually happened to me? I realized that I have all the pieces in place already and merely need to take advantage of the infrastructure already out there.

The details
I started with:

• a working smartphone
• an enterprise monitoring system
• a SoHo router in my home

And that’s pretty much it!

The smartphone doesn’t really matter, as long as it receives emails. I guess a plain old cellphone would work just as well – the messages can be sent as text messages.

For enterprise monitoring I like HP SiteScope because it’s more economical than hard-core systems. I wrote a little about it in a previous post. Nagios is also commonly used and it’s open source, meaning free. Avoid Zabbix at all costs. Editor’s note: OK. I’ve changed my mind about Zabbix some seven years later. It’s still confusing as heck, but now I’m using it and I have to admit it is powerful. See this write-up.

A good SoHo router is Juniper SSG5. It extends the enterprise LAN into the home. You can carve up a Juniper router like that and provide a Home network, Work network, Home wireless and Work wireless. It’s great!

The last requirement is the key. The SoHo router at my house is always on, and so the enterprise LAN is always available, as long as I have power. Get it? I defined a simple PING monitor in SiteScope to ping my SoHo router’s WAN interface, which has a static private IP address on the enterprise LAN. If I can’t ping it, I’ve lost power, and use my monitoring system to send an email alert to my smartphone. When, or in the case of Sandy’s interminable outage, if, power ever comes back on, I send another alert letting me know that as well. If you’re not using SiteScope make sure you send several PINGs. A PING can be lost here or there for various reasons. siteScope sends out five PINGs at a regular interval, as a guideline.

Alternative
Of course if I had a business-class DSL or cable modem service with a dedicated IP I could have just PINGed that, but I don’t. With regaulr consumer grade service your IP can and will change from time to time, and using a dynamic DNS protocol (like dyndns) to mask that problem is a bit tricky.

Yes, if you call the power company they offer to call you back when your power is restored, but I like my monitor better. It tells me when things go off as well as on.

Conclusion
This is my necessity-is-the-mother-of-invention moment. Thank you, Sandy!