= iptables =

Administration tool for IPv4/IPv6 packet filtering and NAT

== Block IP address ==
{{{#!highlight bash
cat /var/log/auth.log | grep Failed
iptables -A INPUT -s 14.39.42.133 -j DROP
iptables -A INPUT -s 80.94.95.181 -j DROP
iptables -A INPUT -s 77.90.185.59  -j DROP
iptables -L
apt install whois
whois 14.39.42.133 
}}}