3 ms·
Here is an overview of what Shodan is: https://help.shodan.io/the-basics/what-is-shodan https://help.shodan.io/the-basics/what-is-shodan The scanning algorith
by achillean 5y ago
Here is an overview of what Shodan is:
https://help.shodan.io/the-basics/what-is-shodan https://help.shodan.io/the-basics/what-is-shodan
The scanning algorithm is mostly just this:
1. Generate a random IPv4 address
2. Select a random port from a list of ~2k ports
3. Check the random IP on the random port
4. Store the result of the check
5. GOTO 1
The above loop runs endlessly and because IPv4 is fairly small it doesn't take long to check everything.
- hnick 5y agoIf everyone somehow magically switched to the much larger IPv6 address space would that be a big problem for you?
- achillean 5y agoWe also crawl IPv6 but it's a very different and more complicated algorithm. We would still end up crawling a sizable chunk but there are obviously unknowns in how biased our dataset would be (i.e. we might index mostly cloud servers and fewer residential devices).
- hnick 5y agoThat's what I thought, you might have to maintain a map of ISPs and such but even then it'd be hard to find all the clients under them.
- 29athrowaway 5y agoIs there a way to opt-out from the scans?