Force all public IP range to be routed trough the default gateway to avoid VPN redirect. All privates IP ranges are not affected

hackVPN.sh

#!/bin/bash

DEFAULT_GW_IP="192.168.1.1" #Local gateway

force_public_route()
{
#netmask -c 0.0.0.0:9.255.255.255
sudo route add -net 0.0.0.0/5 $DEFAULT_GW_IP
sudo route add -net 8.0.0.0/7 $DEFAULT_GW_IP

#netmask -c 11.0.0.0:172.15.255.255
sudo route add -net 11.0.0.0/8 $DEFAULT_GW_IP
sudo route add -net 12.0.0.0/6 $DEFAULT_GW_IP
sudo route add -net 16.0.0.0/4 $DEFAULT_GW_IP
sudo route add -net 32.0.0.0/3 $DEFAULT_GW_IP
sudo route add -net 64.0.0.0/2 $DEFAULT_GW_IP
sudo route add -net 128.0.0.0/3 $DEFAULT_GW_IP
sudo route add -net 160.0.0.0/5 $DEFAULT_GW_IP
sudo route add -net 168.0.0.0/6 $DEFAULT_GW_IP
sudo route add -net 172.0.0.0/12 $DEFAULT_GW_IP

#netmask -c 172.32.0.0:192.167.255.255
sudo route add -net 72.32.0.0/11 $DEFAULT_GW_IP
sudo route add -net 72.64.0.0/10 $DEFAULT_GW_IP
sudo route add -net 172.128.0.0/9 $DEFAULT_GW_IP
sudo route add -net 173.0.0.0/8 $DEFAULT_GW_IP
sudo route add -net 174.0.0.0/7 $DEFAULT_GW_IP
sudo route add -net 176.0.0.0/4 $DEFAULT_GW_IP
sudo route add -net 192.0.0.0/9 $DEFAULT_GW_IP
sudo route add -net 192.128.0.0/11 $DEFAULT_GW_IP
sudo route add -net 192.160.0.0/13 $DEFAULT_GW_IP

#netmask -c 192.169.0.0:223.255.255.255
sudo route add -net 192.169.0.0/16 $DEFAULT_GW_IP
sudo route add -net 192.170.0.0/15 $DEFAULT_GW_IP
sudo route add -net 192.172.0.0/14 $DEFAULT_GW_IP
sudo route add -net 192.176.0.0/12 $DEFAULT_GW_IP
sudo route add -net 192.192.0.0/10 $DEFAULT_GW_IP
sudo route add -net 193.0.0.0/8 $DEFAULT_GW_IP
sudo route add -net 194.0.0.0/7 $DEFAULT_GW_IP
sudo route add -net 196.0.0.0/6 $DEFAULT_GW_IP
sudo route add -net 200.0.0.0/5 $DEFAULT_GW_IP
sudo route add -net 208.0.0.0/4 $DEFAULT_GW_IP

# Thanks to:
# https://serverfault.com/questions/304781/cidr-ranges-for-everything-except-rfc1918
}

flush_route()
{
sudo route -n flush; sudo route -n flush; sudo route -n flush;
route add default $DEFAULT_GW_IP
}

help()
{
cat << EOF
Usage: bash $0 [add, del]

With add you force all public IP to be route through your default gateway
With del you flush all routing and recover default route table
EOF
}

if [ "$1" == "add" ]; then
    force_public_route
elif [ "$1" == "del" ]; then
    flush_route
else
  help $0
fi