Linux免密登录配置出现错误：ssh_exchange_identification: Connection closed by remote host 关联因素： /etc/hosts.deny一
Linux免密登录配置出现错误：ssh_exchange_identification: Connection closed by remote host
关联因素：
/etc/hosts.deny 一般配置如下：
sshd: ALL
/etc/hosts.allow 配置举例：
#l-abc.beta.cn0
sshd: 192.168.1.100
检查配置项，把需要免密登录的ip增加到/etc/hosts.allow文件中
