转发时端口的问题??

Snoopy

[root@Snooopy opt]# nmap 192.168.206.8

Starting nmap V. 3.00 ( www.insecure.org/nmap/ )
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
sendto in send_tcp_raw: sendto(3, packet, 40, 0, 192.168.206.8, 16) => Operation not permitted
Interesting ports on  (192.168.206.8):
(The 1598 ports scanned but not shown below are in state: closed)
Port       State       Service
22/tcp     open        ssh
53/tcp     open        domain
80/tcp     filtered    http

Nmap run completed -- 1 IP address (1 host up) scanned in 4 seconds
[root@Snooopy opt]#

为什么80是过滤的 ??


[root@Snooopy opt]# iptables -t nat -A POSTROUTING -d 192.168.206.8 -p tcp --dport 80 -j SNAT --to 192.168.206.6:80
[root@Snooopy opt]# iptables -t nat -A PREROUTING -s 192.168.206.0/24 -p tcp --dport 80 -j DNAT --to 192.168.206.6:80

其他默认是accept的


浏览器打192.168.206.8等很久,然后出现不能连接,不能实现转发,,怎办啊???