routing.table.sh

#! /bin/bash

# Don't use a routing table record to the interface name (it does not work at least in MacOSX), you shoud use the default router
# sudo route add -host 22.0.0.1 -interface en12 DOES NOT WORK

#Set here the interface name you what to use for the exceptional routes
ETH_NAME="en12"

#write here your LAN DNS Server
DNS_IP="22.0.0.1"

#Exception route list. Traffic sent to $DEST_HOSTS and $DEST_NETS will go through $ETH_NAME interface
DEST_HOSTS="23.4.28.21 22.17.163.203"
DEST_NETS="23.4/16 10.48/16 10.51/16 192.168/16"
#you don't need to change anything else





DEST_HOSTS="$DNS_IP $DEST_HOSTS"

#Get default router for that interface
ETH_ROUTER=$(netstat -nr | grep default | grep $ETH_NAME | awk '{print $2}')

echo "Default router for $ETH_NAME is $ETH_ROUTER"
echo '----------------------'


echo 'Removing old routes. No worries if you get "route... not in table" errors...'
for DEST_HOST in $DEST_HOSTS 
do
  sudo route delete -host $DEST_HOST
  sudo route add -host $DEST_HOST $ETH_ROUTER
done

for DEST_NET in $DEST_NETS
do
  sudo route delete -net $DEST_NET
  sudo route add -net $DEST_NET $ETH_ROUTER
done

#adding dns
# echo
# echo "Adding $DNS_IP and 8.8.8.8 to the DNS table for Wi-Fi"
# sudo networksetup -setdnsservers Wi-Fi $DNS_IP 8.8.8.8

echo
echo 'Done.....'
echo 'Destination        Gateway            Flags        Refs      Use   Netif Expire'
for DEST_HOST in $DEST_HOSTS
do
  netstat -nr  | grep $DEST_HOST
done

for DEST_NET in $DEST_NETS
do
  netstat -nr  | grep $DEST_NET
done

echo "Press any key to dismiss..."
read -rn1