Blocking IP’s using IP Tables
iptables -I
INPUT -s xxx.xxx.xxx.xxx -j DROP
OR just for port 80
Iptables –A INPUT –src xxx.xxx.xxx.xxx –p tcp --dport 80
–j REJECT
Block PING
iptables -A INPUT -p icmp -m state --state NEW -j DROP
Port Redirection
This is useful if you need to access email on a different port due to ISP restrictions.
# Allow
incoming port 587 (tcp) SMTP traffic, and redirect it to port 25
/sbin/iptables
-A INPUT -p tcp --dport 587 -j ACCEPT
/sbin/iptables
-A PREROUTING -t nat -p tcp --dport 587 -j REDIRECT --to-port 25
