packet filter

SYN flood

http://en.wikipedia.org/wiki/SYN_flood

echo 1 > /proc/sys/net/ipv4/tcp_syncookies

XMAS packet

http://en.wikipedia.org/wiki/Christmas_tree_packet

iptables -A INPUT -p tcp –tcp-flags ALL ALL -j DROP

SMURF

http://www.nordu.net/articles/smurf.html

echo 1 > /proc/sys/net/ipv4/icp_echo_ignore_broadcasts

TCP Null

http://lab.gsi.dit.upm.es/semanticwiki/index.php/TCP_Null_Scan

iptables -A INPUT -p tcp –tcp-flags ALL NONE -j DROP