摘要：
telnet；
1、当telnet 某站点或者ip 加 端口号出现 Escape character is '^]' 就说明连接对端的端口成功了。
[root@k8s-node03 ~]# nc -l -p 6996Escape character is ‘^]’.只是一个提示，提示使用Ctrl键+]键可以呼出telnet的命令行。
[root@k8s-master03 ~]# telnet 192.168.31.216 6996
Trying 192.168.31.216...
Connected to 192.168.31.216.
Escape character is '^]'.
^]
telnet> ?
Commands may be abbreviated. Commands are:
close close current connection
display display operating parameters
......
telnet> open
?Already connected to 192.168.31.216