Something

#!/bin/sh -x

## variables ##
tc="/sbin/tc"
iptables="/sbin/iptables"
iproute="/sbin/iproute"
ip="/sbin/ip"

## network interfaces ##
lanif="eth0"
wlanif="ath0"
dmzif="eth1"
vpnif="tun0"
umlif="tap0"
wanif="ppp0"

## network interface ipspace ##
lanip="10.1.0.1"
wlanip="10.2.0.1"
dmzip="10.3.1.1"
vpnip="10.4.0.1"
umlip="10.3.0.1"
wanip="217.151.105.73"

## network segments ##
lanseg="10.1.0.0/24"
wlanseg="10.2.0.0/24"
dmzseg="10.3.1.0/24"
vpnseg="10.4.0.0/24"
umlseg="10.3.0.0/24"
wanseg="217.151.105.72/29"

## default policy ##
$iptables -F
$iptables -X
$iptables -P INPUT DROP
$iptables -P OUTPUT DROP
#$iptables -P FORWARD DROP