Needed

iptables -i INPUT 1 -s 192.168.0.1 -j drop

DNS working Diagram:
http://westwood.wikispaces.com/file/view/dns-recrussion-big.jpg/36711139

DDOS attack checking

netstat -anp |grep 'tcp\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

netstat -anp |grep 'tcp\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n


netstat -tn 2>/dev/null | grep :80 | awk '{print $5}' | cut -f1 -d: | sort | uniq -c | sort -rn | head

dd if=/dev/zero of=/dev/tmpFS bs=1024 count=100000