
MASSCAN: Mass IP port scanner - ntumlin
https://github.com/robertdavidgraham/masscan
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rocgf
Don't get me wrong, I think this is some great coding, but I'm just
wondering... what might be a legal/ethical use this? I'm thinking that most
companies own at most a couple thousand machines, so something more
traditional like nmap might do just fine.

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zorked
There's nothing unethical in port scanning.

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Intermernet
I agree with you, although many years ago I got an official warning from the
head of IT security at the university I was attending (and working at the
computer labs) for allowing a friend of mine to run a port scanning script
across a large portion of the allocated IPv4 address space. Apparently they'd
had complaints... They saw the ethics of port scanning as a grey area, tending
towards black.

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eumoria
I don't really see that. An open port is a door on your house. I'm free to
walk down the street and look at your door as I please. I may also knock on it
as long as I'm not banging on it for 10 minutes or something. However if I
then try to pick the lock and enter your house, well then...

EDIT: It's not a perfect analogy but if you have a system that can be publicly
accessed, just seeing that it's publicly available isn't a grey area to me
that's all.

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modoc
To be fair, if you come to my house, and turn my door knob to see if it's open
or locked, and then start checking all my windows to see if they open or are
locked, then we're going to have trouble...

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eumoria
Can I drive my car through the side? What would be the digital version of
that?

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erelde
I love the pull requests and the messages in data/exclude.conf

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voltagex_
Yep, worth a read, especially if you're considering doing this kind of scan
for yourself.

[https://github.com/robertdavidgraham/masscan/blob/master/dat...](https://github.com/robertdavidgraham/masscan/blob/master/data/exclude.conf#L41)

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dannypgh
Entire IPv4 Internet, I think they mean.

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coldcode
Is it even possible to scan IPv6 internet? Or simply too many IPs
(theoretically) to try?

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cmdrfred
On its face I believe not but, now I'm not positive on the specifics but I
believe there are ip4 to ip6 bridges that index ip6 addresses and allow you to
only scan active addresses.

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dannypgh
No. There are 2^128 or so possible IP addresses. Such an index wouldn't fit
anywhere.

I think you're thinking of 6to4, which maps a /64 onto every v4 address. But
allocation within the /64 may still be super sparse...

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RIMR
Been using this software as well as Zmap for Internet-wide scans for the past
three years. This kind of software is scary powerful.

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billmalarky
What do you use it for? Academic research?

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CSDude
It is great. My mobile career exposed a huge /8 network and we could even scan
it to find some lonely IoT devices with default root passwords with masscan in
minutes.

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libeclipse
Why is this just making its way to HN front page right now?

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jaytaylor
It's probably been submitted again now on the heels of DefCon and Blackhat,
where Robert Graham usually gives cool talks and presentations about his
security research and work, e.g. MASSCAN.

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ntumlin
That might explain the popularity of it, but I actually found it from poking
around on jvns.ca from the recent post about how gdb works.

