If you have a laptop that uses dhcp to move between networks, high security
setting in lokkit will cause dns problems.
high securtiy only allows responses from a set of ips, however when you
switch networks, this set might change, thus not allowing you to get the
proper dns responses.

This is also likely to cause a problem for people who manually switch
without dhcp.  Perhaps you could have the rules for allowing dns responses
to be dynamic, based on the dns servers currently in resolv.conf when the
interface is brought up.