mattia-beta

### 1: Drop invalid packets ###
/sbin/iptables -t mangle -A PREROUTING -m conntrack --ctstate INVALID -j DROP

### 2: Drop TCP packets that are new and are not SYN ###
/sbin/iptables -t mangle -A PREROUTING -p tcp ! --syn -m conntrack --ctstate NEW -j DROP

### 3: Drop SYN packets with suspicious MSS value ###
/sbin/iptables -t mangle -A PREROUTING -p tcp -m conntrack --ctstate NEW -m tcpmss ! --mss 536:65535 -j DROP

### 4: Block packets with bogus TCP flags ###