UDP queries without a DNS Cookie receive REFUSED responses with the TC flag set,
that may trigger fall back to TCP for those clients.
.IP
-By default only localhost is \fIallow\fRed, the rest is \fIrefuse\fRd.
+By default only localhost (the 127.0.0.0/8 IP netblock, not the loopback
+interface) is implicitly \fIallow\fRed, the rest is \fIrefuse\fRd.
The default is \fIrefuse\fRd, because that is protocol\-friendly. The DNS
protocol is not designed to handle dropped packets due to policy, and
dropping may result in (possibly excessive) retried queries.
.IP
The action is the same as the ones defined under \fBaccess\-control:\fR.
Interfaces are \fIrefuse\fRd by default.
-By default only localhost (the IP netblock, not the loopback interface) is
-\fIallow\fRed through the default \fBaccess\-control:\fR behavior.
+By default only localhost (the 127.0.0.0/8 IP netblock, not the loopback
+interface) is implicitly \fIallow\fRed through the default
+\fBaccess\-control:\fR behavior.
+This also means that any attempt to use the \fBinterface-*:\fR options for the
+loopback interface will not work as they will be overridden by the implicit
+default "\fBaccess\-control:\fR 127.0.0.0/8 allow" option.
.IP
Note that the interface needs to be already specified with \fBinterface:\fR
and that any \fBaccess-control*:\fR setting overrides all \fBinterface-*:\fR