The Netsweeper Policy Service feature for Reverse DNS (RDNS) filtering is used to map requests to IP addresses back to the hostname associated with the specific IP address. For more information on how the RDNS works please see How does the RDNS work when filtering HTTPS in Netsweeper?
RDNS can indeed be disabled. To do this you simply make all lists no longer trigger a hostname resolution.
Slowing down RDNS
It would be recommended to keep RDNS enabled, and rather change the resolution rates to a lower level. These entries you can adjust to a much much lower level.
Disabling the RDNS Lookup during policy processing
To disable the policy request http://IP or https://IP to check the RDNS cache, you can disable this by using
It is important to remember, that we will still resolve the hostname entries if only the above setting is changed, but we will not use the cache to perform any IP to hostname lookups.