telent对端口检测状态分析

    telnet基于TCP/IP协议通信的，把远程的shell反弹回本地！

yum install -y telnet     

apt-get  install telnet

###端口被封，有墙堵住

[root@DZSWJ_FZJH1 ~]# telnet 86.103.72.41 80

Trying 86.103.72.41...

###端口开放，服务未启动

[root@WWMYSQL ~]# telnet 10.104.0.10 10051

Trying 10.104.0.10...

telnet: connect to address 10.104.0.10: Connection refused

###端口开放，服务也开启

[root@WWMYSQL ~]# telnet 10.104.0.12 22

Trying 10.104.0.12...

Connected to 10.104.0.12.

Escape character is '^]'.

SSH-2.0-OpenSSH_7.3

                            虚无止境，活若菩提！