Comment 4 for bug 1544705

fair enough. By the way, I call my iptables script from my interfaces file:

# interfaces file for smythies.com 2016.01.30
# attempt to set local DNS herein, as the method
# used with the old 12.04 server no longer works.
#
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback
pre-up /home/doug/init/doug_firewall
dns-nameservers 127.0.0.1

# The primary interface (d-link PCI card)
auto enp4s0
iface enp4s0 inet dhcp

# Local network interface (uses built in ethernet port)
auto enp2s0
iface enp2s0 inet static
  address 192.168.111.1
  network 192.168.111.0
  netmask 255.255.255.0
  broadcast 192.168.111.255