sub IFACE {
  my $pattern = shift @_;
  my $result;
  foreach $iface (@_) {
    $result .= (eval "\"$pattern\"") . "\n";
  }
  chomp $result;
  return $result;
}

&utter( <<"EOF" );
iptables -t nat -N outbound-DMZ
@{[ &IFACE(
  "iptables -t nat -A outbound-DMZ -s $lanCidr -o \$iface -j SNAT --to-source $dmzIp",
(keys %ipAddress)) ]}
iptables -t nat -A outbound-DMZ -j RETURN
EOF