I've just installed mDNSResponder on a FreeBSD 10.2 jail.
The port has no user-configurable options that I can find, and no switches.
However, when I start it, it fails to come up:
# mdnsd -debug
mDNSResponder (Engineering Build) (Feb 1 2016 17:40:48) starting
socket AF_INET6: Protocol not...