It should not be difficult to limit ANY queries on Linux systems. Something such as this perhaps (which could be tweaked in various ways): iptables -A INPU

It should not be difficult to limit ANY queries on Linux systems. Something such as this perhaps (which could be tweaked in various ways): iptables -A INPUT -p udp --dport 53 -m string --from 50 --algo bm --hex-string "|0000FF0001|" -m recent --rcheck --seconds 10 --hitcount 5 -j DROP For IPv6, just replace 'iptables' with 'ip6tables'. I imagine OpenBSD's PF could do this as well.