Hi all Yesterday there was a discussion about kernel options like tcp_syncookies. Exactly to this matter I hope to get an answer to the following: Taken from http://www2.little-idiot.de/firewall/zusammen-49.html I quote: Syn cookies sollte man ausschalten, zumal diese einen Angriff nur dann verhindern, wenn der Angreifer mit LINUX und aktivierten SYN Cookies arbeitet. Ansonsten sind diese fur DoS anfallig. End of quote. Translation: Syn cookies should be disabled. An attack can only be prevented, if the attacker uses with Linux and SYN cookies activated as well. SYN cookies enabled is susceptible on DoS. Please don't hang me because of translation erros. Does anybody have more information (I do not mean www.bb-zone.com - I didn't find much there) about this? Whether it is true and mainly what DoS attacks it does not defend against? Thank you Philipp