1.iptables -A INPUT -p icmp -j REJECT

2.iptables -A INPUT -p tcp --dport 80 -j REJECT

3.iptables -A INPUT -m connlimit --connlimit-above xxx -j REJECT

4.A7:GATEWAY=192.168.1.129
B8:GATEWAY=10.0.0.8
A8:vim /etc/sysctl.conf net.ipv4.ip_forward=1
sysctl -p

            iptables -A FORWARD -j REJECT
            iptables -I FORWARD -s 10.0.0.0/24 -m state --state NEW -j ACCEPT
            iptables -I FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
            iptables -I FORWARD 3  -d 10.0.0.18 -p tcp -dport 22 -j ACCEPT