StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POReverse DNS in Ruby?
text
Body
copied!<p>I'm in an environment with a lot of computers that haven't been properly inventoried. Basically, no one knows which IP goes with which mac address and which hostname. So I wrote the following:</p> <pre><code># This script goes down the entire IP range and attempts to # retrieve the Hostname and mac address and outputs them # into a file. Yay! require "socket" TwoOctets = "10.26" def computer_exists?(computerip) system("ping -c 1 -W 1 #{computerip}") end def append_to_file(line) file = File.open("output.txt", "a") file.puts(line) file.close end def getInfo(current_ip) begin if computer_exists?(current_ip) arp_output = `arp -v #{current_ip}` mac_addr = arp_output.to_s.match(/..:..:..:..:..:../) host_name = Socket.gethostbyname(current_ip) append_to_file("#{host_name[0]} - #{current_ip} - #{mac_addr}\n") end rescue SocketError => mySocketError append_to_file("unknown - #{current_ip} - #{mac_addr}") end end (6..8).each do |i| case i when 6 for j in (1..190) current_ip = "#{TwoOctets}.#{i}.#{j}" getInfo(current_ip) end when 7 for j in (1..255) current_ip = "#{TwoOctets}.#{i}.#{j}" getInfo(current_ip) end when 8 for j in (1..52) current_ip = "#{TwoOctets}.#{i}.#{j}" getInfo(current_ip) end end end </code></pre> <p>Everything works except it does not find a Reverse DNS.</p> <p>Sample output that I'm getting is this:</p> <pre><code>10.26.6.12 - 10.26.6.12 - 00:11:11:9B:13:9F 10.26.6.17 - 10.26.6.17 - 08:00:69:9A:97:C3 10.26.6.18 - 10.26.6.18 - 08:00:69:93:2C:E2 </code></pre> <p>If I do <code>nslookup 10.26.6.12</code> then I get the correct reverse DNS so that shows that my machine is seeing the DNS server.</p> <p>I have tried <code>Socket.gethostbyname</code>, <code>gethostbyaddr</code>, but it doesn't work.</p> <p>Any guidance will be much appreciated.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload