Nmap Development mailing list archives
Re: Review: Angry IP Scanner
From: Brandon Enright <bmenrigh () ucsd edu>
Date: Fri, 6 Jun 2008 02:05:52 +0000
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Fri, 6 Jun 2008 02:27:45 +0530 "Kris Katterjohn" <katterjohn () gmail com> wrote: ...snip...
One thing I do like about it is the ability to narrow down the random IP generation to a given base IP and netmask. This may not be easy to implement in Nmap (since a user may or may not want a reserved IP, and the random IP generation code would have to be changed to allow for this), and probably not worth it. For example, if you wanted random IPs in the range of 192.*.*.*, should 192.168 be chosen or not? It's still pretty cool, though.
This *is* nice and I've thought about implementing it for Nmap but every time I give it serious thought I decide that outputting all the IPs to a list with -sL and then a random section from that list is a better way to do it. Do you know if Angry IP Scanner generates collisions (birthday paradox)? Say you wanted to scan 64 random IPs out of a /24... You'd expect 7.28 duplicates. Not that bad... Now suppose you wanted to scan a random section of 10,000 IPs out of a /16, you'd get 725.5 duplicates. That's a lot of repeat work. I'm not aware of any generic algorithm, method, or technique that could generate numbers in some arbitrary set of ranges without duplicates that is both fast and memory efficient. Creative use of a Bloom Filter (http://en.wikipedia.org/wiki/Bloom_filter) would work but that starts to get pretty damn time-consuming to do right... Nmap's current -iR doesn't have to worry about duplicates (much) because picking from .75 * 2^32 is a lot of sample space. Brandon -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEARECAAYFAkhIm4YACgkQqaGPzAsl94KFeACeJgxoSB18R2aTobULNKW+UeF0 SKQAoMPBEla8KhtvfsA9llGp9FHhiU/d =5kKW -----END PGP SIGNATURE----- _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- Review: Angry IP Scanner Kris Katterjohn (Jun 05)
- Re: Review: Angry IP Scanner doug (Jun 05)
- Re: Review: Angry IP Scanner Fyodor (Jun 05)
- Re: Review: Angry IP Scanner Brandon Enright (Jun 05)
- Re: Review: Angry IP Scanner doug (Jun 06)
- Re: Review: Angry IP Scanner bensonk (Jun 06)
- Re: Review: Angry IP Scanner Brandon Enright (Jun 06)
- Re: Review: Angry IP Scanner doug (Jun 06)
- Re: Review: Angry IP Scanner doug (Jun 06)