iptables添加防火墙限制，允许某ip或网段访问此端口

1、在tcp协议中，禁止所有的ip访问本机的80端口
[root@node1 ~ 17:11:28]# iptables -I INPUT -p tcp --dport 80 -j DROP
[root@node1 ~ 17:13:54]#  service iptables save
iptables: Saving firewall rules to /etc/sysconfig/iptables:[  OK  ]
[root@node1 ~ 17:13:58]# service iptables restart
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
iptables: Applying firewall rules:                         [  OK  ]
[root@node1 ~ 17:14:01]# 
2、只允许192.168.200.199访问本机的80端口
[root@node1 ~ 17:15:35]# iptables -I INPUT -s 192.168.200.199 -p tcp --dport 80 -j ACCEPT
[root@node1 ~ 17:16:05]#  service iptables save
iptables: Saving firewall rules to /etc/sysconfig/iptables:[  OK  ]
[root@node1 ~ 17:16:07]# service iptables restart
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
iptables: Applying firewall rules:                         [  OK  ]
[root@node1 ~ 17:16:10]# 
如要配置允许某个网段的ip进行访问：
iptables -I INPUT -s 192.168.200.0/24 -p tcp --dport 80 -j ACCEPT