嵌入式linux开发，连接busybox的telnetd服务，报错：Connection closed by foreign host.

 一、问题描述。

        嵌入式linux开发，连接busybox的telnetd服务，报错如下：

telnet 198.168.1.25
Trying 198.168.1.25...
Connected to 198.168.1.25.
Escape character is '^]'.
Connection closed by foreign host.

二、问题分析。

        被服务端拒绝。

三、解决方案。

        修改内核配置，启用Legacy (BSD) PTY support。

Device Drivers --->
    Character devices --->
        -*-  Unix98 PTY support
        []  Support multiple instances of devpts
        [*]  Legacy (BSD) PTY support
        (256)  Maximum number of legacy PTY in use