Simulates network disconnection over SSH by dropping all traffic to/from any host other than the host calling the script

killnet

#!/bin/bash

#Determine IP of calling user
ssh_ip=`echo $SSH_CLIENT | awk '{ print $1}'`

if [ "$1" == "kill" ]; then

echo "Simulating network disconnection by dropping traffic from all hosts except $ssh_ip..."

#Default Policy to DROP all incoming traffic
sudo iptables -P INPUT DROP
sudo iptables -P OUTPUT DROP

#Allow traffic from/to calling IP
sudo iptables -A INPUT -s $ssh_ip -j ACCEPT
sudo iptables -A OUTPUT -d $ssh_ip -j ACCEPT

elif [ "$1" == "resume" ]; then

echo "Resuming network connectivity..."

sudo iptables -P INPUT ACCEPT
sudo iptables -P OUTPUT ACCEPT

else

echo "$0 simulates network disconnection over SSH by dropping all traffic to/from any host other than the host calling the script over SSH"
echo
echo "Usage: $0 <kill/resume>"

fi