Throttling Example


        # ipfwthrottle -S -m 0xffff0000 -T SMTP-throttle 25/60
        # ipfwthrottle -S -m 0x0000ffff -T DNS-throttle 50/1

        tcp && dstport(smtp/tcp) && !established && !call("SMTP-throttle") {
                 reject;
        }
        udp && dstport(domain/udp) && !call("DNS-throttle") {
                reject;
        }