ssh连接问题

1.问题:Permission denied,please try again.

可能原因:密码错误或者对方主机不允许root用户远程登录

针对第二个原因解决方案:修改ssh服务端配置文件:vim /etc/ssh/sshd_config

# Authentication:

#LoginGraceTime 2m
#PermitRootLogin prohibit-password
PermitRootLogin yes? ?添加这一句可以允许root用户远程登录
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10

然后再重启ssh服务:service ssh restart

2.问题:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:BCqRWpcHuCP7H2Hu9vKVhOHWbumgivtO1WdLuFmjd9k.
Please contact your system administrator.
Add correct host key in /home/guojihai/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /home/guojihai/.ssh/known_hosts:2
remove with:
ssh-keygen -f "/home/guojihai/.ssh/known_hosts" -R "192.168.199.134"
ECDSA host key for 192.168.199.134 has changed and you have requested strict checking.
Host key verification failed.

可能原因分析:可能是之前登录过对方主机,但是对方改变了密码,所以需要主机的验证失败

解决方案:ssh-keygen -f "/home/guojihai/.ssh/known_hosts" -R "192.168.199.134"

然后重新登录:ssh [email?protected]

3.问题:碰见refused等问题

可能原因:可能是主机地址写错,或者是对方主机没有安装ssh服务端程序

针对第二个原因解决方案:在对方主机上执行命令:sudo apt-get install openssh-server

然后查看服务端程序是否启动:ps -e |grep ssh

如果看到sshd,证明安装启动成功,可以允许其他主机远程连接