iptables配置又回到最初默认配置？这是为啥？:配置报错 

redhat linux6.5下执行/etc/rc.d/init.d/iptables save后iptables配置又回到最初默认配置？这是为啥？

修改后的配置：
[root@ZHUANFA ~]# vi /etc/sysconfig/iptables # Firewall configuration written by system-config-firewall

# Manual customization of this file is not recommended.

*filter

:INPUT ACCEPT [0:0]

:FORWARD ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

-A INPUT -p icmp -j ACCEPT

-A INPUT -i lo -j ACCEPT

-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

-A INPUT -j REJECT --reject-with icmp-host-prohibited

-A FORWARD -j REJECT --reject-with icmp-host-prohibited

COMMIT

iptables -t nat -A POSTROUTING -s 192.10.1.0/24 -o eth0 -j SNAT --to 200.10.1.10

iptables -t nat -A PREROUTING  -i eth0 -p tcp --dport 8080 -j DNAT --to 192.10.1.220:80
执行[root@ZHUANFA ~]# /etc/rc.d/init.d/iptables save iptables: Saving firewall rules to /etc/sysconfig/iptables:[  OK  ]
后，再查看iptables配置，又回到最初的默认配置！！
[root@ZHUANFA ~]# cat /etc/sysconfig/iptables # Generated by iptables-save v1.4.7 on Wed Apr  1 10:27:17 2015 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [14:1660] -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT  -A INPUT -p icmp -j ACCEPT  -A INPUT -i lo -j ACCEPT  -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT  -A INPUT -j REJECT --reject-with icmp-host-prohibited  -A FORWARD -j REJECT --reject-with icmp-host-prohibited  COMMIT # Completed on Wed Apr  1 10:27:17 2015 [root@ZHUANFA ~] 这是为啥？？？？