diff --git a/modules/dhcp_common/free_ips.rb b/modules/dhcp_common/free_ips.rb
index 5bc32f9..78893ed 100644
--- a/modules/dhcp_common/free_ips.rb
+++ b/modules/dhcp_common/free_ips.rb
@@ -2,6 +2,7 @@ require 'concurrent'
 require 'logger'
 require 'set'
 require 'dhcp_common/pingable'
+require 'resolv'
 
 module Proxy::DHCP
   class FreeIps
@@ -72,8 +73,13 @@ module Proxy::DHCP
           if tcp_pingable?(possible_ip) || icmp_pingable?(possible_ip)
             logger.debug "Found a pingable IP(#{possible_ip}) address which does not have a Proxy::DHCP record."
           else
-            logger.debug "Found free IP #{possible_ip} out of a total of #{num_of_addresses} free IPs."
-            return possible_ip
+            begin
+              name = Resolv.getname(possible_ip)
+              logger.debug "Found DNS record #{name} on IP(#{possible_ip}) address, this addresse seems to be used"
+            rescue Exception => e
+              logger.debug "Found free IP #{possible_ip} out of a total of #{num_of_addresses} free IPs."
+              return possible_ip
+            end
           end
         rescue Exception => e
           logger.error("Exception when pinging #{possible_ip}. Skipping the address.", e)