Re: [BULK] Re: need help with ping of list by name

[David Fifield <david () bamsoftware com>]

On Fri, Apr 16, 2010 at 02:12:30PM -0500, Norris Carden wrote:
> What I am trying to do is take a very long list of system names
> enumerated from Active Directory and identify systems that do not exist.
> All I have is computer names. I was hoping Nmap would be able to help me
> with this.
>
> Here are my assumptions:
>
> A system that exists will respond to a ping. I can easily assume these
> exist.
> A system that does not respond to a ping, but has a DNS entry might
> still exist, but is currently powered down.
> A system that has no DNS entry either never existed or has been powered
> off long enough for their DDNS entry to expire. These are the systems I
> am trying to identify.

Are you talking about forward (hostname to IP) or reverse (IP to
hostname) DNS? If I understand you right, the list scan -sL is what you
want. That will print a list of all the target you specify, along with
their forward and reverse DNS names. Systems that don't have forward DNS
entries will say "Failed to resolve given hostname/IP: xxx".

David Fifield
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