CSF is blocking DNS requests

[Cerberuz]

Hi, I've just had to change my nameserver IP addresses, my host done this for me (my hosting is colocated) and then sent me a message saying that when CSF is enabled CSF blocks DNS requests.

With CSF enabled the DNS servers do not respond
With CSF disabled the DNS servers do respond

Any help resolving this issue will be greatly appreciated.

Pete

[ItsJustMe]

Make sure port 53 is open, both UDP and TCP.