Tracking down reverse for ip

James Hess mysidia at
Fri Apr 16 00:52:31 CDT 2010

On Thu, Apr 15, 2010 at 3:59 PM, William Pitcock
<nenolod at> wrote:
> For someone who is a CCNA, Mikrotik Certified Whatever, etc, etc, etc,
> you really should know how to use dig(1).

Certifications usually only suggest certain skills or knowledge they
were designed to validate,  and sometimes might fail even at that;
dig(1) or detailed DNS knowledge  is not scoped within either of those
certs, as far as I know..

There are probably many CCNA and MTCNA  holders who have not so much
as seen a Unix/Linux shell prompt,  and maybe only saw a DOS/Windows
command prompt  once or twice,   so the only shell command known is

[snip snip-]
> On Thu, 2010-04-15 at 15:07 -0500, Dennis Burgess wrote:
>> I have a customer that has an IP of Currently, I can not
>> get any reverse on this IP.
>> What is the best way to find out the responciable servers for this?

There are a number of ways to further research an IP address.   Your
first stop should be normal WHOIS on the IP, either from your favorite
command line,  or a web-based service such as  DNSTools, DNSStuff, or
Robtex as in

If no success.... then check the DNS system to determine what
nameservers (if any) are delegated for the IP address' reverse DNS,
finally  check prefix whois, RADB, or various services to lookup the
AS associated with world BGP announcements for the address. Asking OPs
mailing lists to help identify responsible party should be very last
after all normal avenues are exhausted.


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