usage() {
cat <<EOF
usage: ${0##*/} [OPTS] start|stop NS_NAME
-Nat a network namespace. create a mount ns. systemd friendly
+Nat a network namespace. systemd friendly
+
+Also creates a mount namespace with a cloned /etc/resolv.conf.
-c, --create Create a named network namespace. When running from
the same network namespace as pid 1, this is set automatically.