How can I find any domain name that resolves to IP within a given net range?

Question

For example, given the range:

172.128.0.0 - 172.191.255.255

I need to find some domain that resolves to an IP-adress within the range. Is it possible ? I'm using a Linux system.

Answer 1

Well, the DiG utility (man dig) can do reverse-DNS lookups to see if a given IP address has an associated DNS record. AFAIK it only accepts a single address at a time, but you could use some bash looping to generate the commands to check all the addresses.

for i in $(seq 128 191) ; do 
  for j in $(seq 1 255) ; do
    for k in $(seq 1 255) ; do
      dig -x 172.$i.$j.$k
      sleep 5
    done
  done
done

In one line:

for i in $(seq 128 191) ; do for j in $(seq 1 255) ; do for k in $(seq 1 255) ; do dig -x 172.$i.$j.$k ; sleep 5 ; done ; done ; done

You might want the +short option (or other options) to help get the output into some meaningful form. See man dig for possible options; here's the syntax:

dig +short -x 172.$i.$j.$k

Answer 2

There are many online tools that do this on an IP by IP basis, eg:

• http://www.yougetsignal.com/tools/web-sites-on-web-server/
• http://domainbyip.com/
• http://sameip.org/

Answer 3

I take a chance, I'm not sure if my answer is good...

http://lists.samba.org/archive/samba-ntdom/1999-June/005094.html

Thanks, David