On logstash 6.2.4 we are parsing events with CIDR

        cidr {
          address => [ "%{IPAddress]}" ]
          network_path => "/etc/logstash/dictionaries/CIDR.yaml"
          add_tag => [ "tagging" ]
        }

the dictionary file contains around 4.000 entries and we are parsing around 1.000 events/second. This cause a very high load on logstash. If we are parsing the same events without this command, the load goes from 3000 to 150.
Please note that we have lot of other parsing activities on the same events like different translates where the yaml file contains also around 4.000 events, but this parsing seem's not causing a high load

We can reproduce the performance issue without problems. It would be nice to have a solution for this problem.