1.输入vi /etc/ssh/sshd_config，按回车键

2.找到 TCPKeepAlive yes把前面的#去掉

3.找到ClientAliveInterval 参数去掉前面的#，将ClientAliveInterval后面的0改成60

4.按“ESC”键输入wq按回车键保存退出vi编辑

5.在putty客户端点击Connection,在Seconds between keepaliaves设置为60.然后勾选Enable TCP_keepalives后再进行连接即可