Is there a rule for iptables to limit the amount of SYN packets a /24 range of IPs can send?

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http://askubuntu.com – How can I block entire C class IP blocks when they send too many SYN packets to my ubuntu 12.04 server? Example of what I see during a SYN flood attack: Each different IP only sends 1 SYN packet, so the firewall doesn't block it. But the range 192.132.209.* all together is sending a lot of SYN packets in a very small time period. (HowTos)