Reasons for being rejected immediately after telnet
The phenomenon is that
22.188, telnet 22.122 can be connected, as follows
22.152, telnet 22.122 error, as follows
at first thought it was a problem of 22.122 network rules, and was rejected by 122.
Later, through the Internet,
means that the application was rejected instead of the server configuration.
Then I shut down the 22.152 application, telnet again, and the problem was solved.