Nmap Development: RE: wishlist item: paralellized list scan

["Craig Humphrey" <Craig.Humphrey () chapmantripp com>]

I wrote some perl scripts for doing bulk DNS grinding.  I think I've
still got them somewhere...  You could set how many threads to use.  If
I can find them, do you want a copy?  They're fairly basic.

[background]
I wanted to put a block on all ADSL users for an ISP since we were
getting an excessive amount of noise from them.
I knew the pattern an ISP used for their ADSL DNS entries, but because
they didn't have one contiguous IP address space, I had to grind their
DNS space, generating IP lists, which I converted to ranges that I could
block.

Normally you can get whois to return enough info for getting IP ranges,
but they'd sublet parts of their blocks to customers and their ADSL
ranges were scattered about... Fun.

Some places now "mark" their IP rages for particular uses (e.g.
ADSL/cable/dial-up "dynamic" users, as opposed to "static"
clients/services).

Later'ish
Craig


> -----Original Message-----
> From: Alan Jenkins [mailto:sourcejedi () phonecoop coop] 
> Sent: Thursday, September 30, 2004 8:17 AM
> To: nmap-dev () insecure org
> Subject: wishlist item: paralellized list scan
>
> The list scan, nmap -sL, doesn't run in parallel - only one 
> DNS query runs at 
> a time.  It is potentially useful to to be able to scan a 
> large network 
> address space for machines with a registered hostname.
>
> Is this technically feasible?
> Would it be too much work to implement in nmap?
>
> A little research suggests that nmap uses gethostbyaddr, 
> which blocks until 
> the host is resolved - and that therefore it would be 
> necessary to send dns 
> requests manually - perhaps after first looking in /etc/hosts 
> (assuming using 
> multiple threads or processes is not really an option)
>
> Does anyone know a tool capable of doing this already?
>
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