出错现象：
[root@localhost ~]# telnet 192.168.1.128
Trying 192.168.1.128...
telnet: connect to address 192.168.1.128: No route to host
telnet: Unable to connect to remote host: No route to host
解决办法：
在telnet服务器上执行：iptables -F
出错现象：
[root@localhost ~]# telnet 192.168.1.128
Trying 192.168.1.128...
telnet: connect to address 192.168.1.128: No route to host
telnet: Unable to connect to remote host: No route to host
解决办法：
在telnet服务器上执行：iptables -F