telnet协议服务器默认通信端口是,Linux telnet服务器不使用telnet协议握手

我们正在尝试使用简单的终端程序连接到Linux telnet服务; 我怀疑服务器设置为默认VT-100，并且telnet服务器发送控制握手序列，期望终端用其支持的选项进行回复，并挂起等待终端回复。

We are trying to connect to Linux telnet service using simple terminal program; I suspect server is set to default VT-100, and telnet server sends control handshake sequences, expecting terminal to reply with its supported options, and hangs waiting for terminal reply.

[](https://i.stack.imgur.com/X0l9s.jpg) (apologies for poor quality of image)

不幸的是，终端只是裸通信程序而且不了解telnet协议。

Unfortunately terminal is just bare communication program and does not know about telnet protocol.

有没有办法告诉telnet服务器(例如通过设置特定的终端类型)不要开始识别远程终端属性，而是直接进入通信？

Is there any way to tell to telnet server (e.g. through setting specific terminal type) not to start identification of remote terminal properties, but go directly to the communication?

编辑：

Edit:

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> 请使用更多详细信息编辑问题：您使用的是什么终端，什么是"裸通信"？ 程序是吗？

》 Please edit question with more details: What terminal are you using, what "bare communication" program is it?

通讯程序打开与Linux PC到端口23的TCP连接，然后发送键盘上输入的字符，并显示屏幕上收到的字符，无需任何字符处理。

Communication program opens TCP connection to the linux PC to port 23, then sends characters typed on the keyboard and displays characters received on the screen without any character processing.

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> 你可以在服务器上运行netcat而不是telnetd，如果通信本身正常工作，可以用它来调试

》 Can you run netcat on the server instead (or in addition) of telnetd, and use this to debug if the communication by itself is working

我不确定，我不控制两台机器。 但是100％事实是机器运行终端能够连接到linux机器，并且linux机器能够发送telnet协议控制字符(你可以在图片上看到它 - 白色字符是0xff - telnet选项的开始标记)。 我不能说100％因为我没有Wireshark日志，但似乎通信工作正常，并且它是telnet服务器，它不通过telnet协议握手。

I am not sure, I do not control both machines. But is it 100% fact that machine running terminal is able to connect to the linux machine, and linux machine is able to send telnet protocol control characters (you can see it on the picture - white chars are 0xff - start marker of telnet option). I can not say 100% because I do not have Wireshark logs, but seems communication works properly, and it is telnet server which does not pass through telnet protocol handshake.

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> 连接后，您想要登录，还是想要做其他事情？ 你能在终端上使用更安全的东西，例如SSH？

》 Once you are connected, do you want to login, or do you want to do anything else? Can you use something safer on the terminal, e.g. ssh?

是的，我希望telnet服务器显示"login：" 要求登录系统。 Linux机器上的telnet服务是可操作的，因为可以使用telnet客户端从第三台机器上记录它 - 但是这个telnet客户端知道telnet协议并响应它。 在上述情况下，temrinal程序对telnet控制代码/协议一无所知，并将其显示为字符而无需任何进一步操作(根据telnet协议进行响应)。

Yes, I want telnet server to display "login: " asking to log into the system. telnet service on the linux machine is operational, because it is possible to log it from third machine using telnet client - but this telnet client is aware about telnet protocol and responds to it. In the case described above temrinal program knows nothing about telnet control codes/protocol, and displays them as characters without any further action (response according to telnet protocol).