> -----Original Message----- > > Is netfilter capable of knowing when someone is crafting SMTP (or FTP or > > HTTP or ...) packets that violate RFC rules to exploit a vulnerability > > in some server? Snort is an excellent "tool"/Network Intrusion Detection System. You might also be interested in this: http://l7-filter.sourceforge.net/ Snort is more robust, but also more complex. <> Jim