How to lock down SSH access

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# LOCK DOWN
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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 (SSH PORT)-j ACCEPT
/sbin/iptables -A OUTPUT -p tcp -d $IP –sport (SSH PORT)-j ACCEPT
done
iptables -A INPUT -p tcp –dport (SSH PORT) -j DROP
iptables -A OUTPUT -p tcp –sport (SSH PORT)-j DROP

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