Aktiver CONFIG_SYN_COOKIES

hvis jeg ikke husker meget galt så skal du genoversætte din kerne for at få det aktiveret.

smid følgende ind i rc.local og genstart
echo 1 > /proc/sys/net/ipv4/tcp_syncookies

space-> Det er ikke det han mener. Han vil gerne have den kernel option der hedder config_syn_cookies aktiveret.
Mon ikke RedHat eventuelt har den som modul. Jeg kan bare ikke huske modul navnet.

Men ellers are spaces forslag godt nok, idet:

3.3.26. tcp_syncookies
The tcp_syncookies variable is used to send out so called syncookies to hosts when the kernels syn backlog queue for a specific socket is overflowed. This means that if our host is flooded with several SYN packets from different hosts, the syn backlog queue may overflow, and hence this function starts sending out cookies to see if the SYN packets are really legit.

This variable is used to prevent an extremely common attack that is called a "syn flood attack". The tcp_syncookies variable takes an boolean value which can either be set to 0 or 1, where 0 means off. The default setting is to turn this function off.

Du kan læse meget mere om Ipsysctl på http://ipsysctl-tutorial.frozentux.net/ipsysctl-tutorial.html