ARP poisoning mitigation

arp_tables_mitigation.sh

#!/bin/sh

# Set the router IP and MAC addresses before running the script
ROUTER_IP_ADDRESS=192.168.0.1
ROUTER_MAC_ADDRESS=10:FE:ED:4F:FD:3A

arptables -P INPUT DROP
arptables -P OUTPUT DROP

# Only accept arp requests from my router.
arptables -A INPUT -s $ROUTER_IP_ADDRESS --source-mac $ROUTER_MAC_ADDRESS -j ACCEPT

# Send replies only to my router.
arptables -A OUTPUT -d $ROUTER_IP_ADDRESS --destination-mac $ROUTER_MAC_ADDRESS -j ACCEPT

# Add a static entry into the ARP table to link the router to its own MAC.
arp -s $ROUTER_IP_ADDRESS $ROUTER_MAC_ADDRESS

exit 0