The folks at ZMAP have released version 1.02 of their scanning tool ( https://zmap.io/ )

ZMAP's claim to fame is it's speed - the developers indicate that with a 1Gbps uplink, the entire IPv4 space can be scanned in roughly 45 minutes (yes, that's minutes) with non-specialized hardware, which is getting close to 100% efficiency on a 1Gbps NIC.   Note that even now, you should design your hardware carefully to get sustained 1Gbps transfer rates.  While not many of us have true 1Gbps into our basements, lots of us have that at work these days. 

With this tool out, look for more "internet census" type studies to pop up.  Folks, be careful who you scan - strictly speaking, you can get yoursefl in a lot of trouble probing the wrong folks, especially if you are in their jurisdiction!

It's also worth mentioning that running a tool like this can easily DOS the link you are scanning from.  Taking 100% of your employer's bandwidth for scanning is good for a whole 'nother type of discussion.

It's safest to get a signed statement of work, and run this on a test subnet before using it "for real".  If anyone has used ZMAP in a production scan, please use our comment form to let us know how you found the tool

Scan safe everyone!

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Rob VandenBrink
Metafore