Lock Down SSH - Restrict certain IP to SSH

Save as sshlockdown.sh

chmod +x sshlockdown.sh

./sshlockdown.sh

##########################
# LOCK DOWN
##########################
SSHPORT=22

for IP in 111.111.111.111 222.222.222.222 333.333.333.333 444.444.444.444/27 ; do
/sbin/iptables -A INPUT -p tcp -s $IP –dport $SSHPORT -j ACCEPT
/sbin/iptables -A OUTPUT -p tcp -d $IP –sport $SSHPORT -j ACCEPT
done
iptables -A INPUT -p tcp –dport $SSHPORT -j DROP
iptables -A OUTPUT -p tcp –sport $SSHPORT -j DROP

#####################

Lock Down SSH – Restrict certain IP to SSH