Centos7 virtual machine created ssh login

surroundings

Virtual Machine installed operating system version: CentOS Linux release 7.6.1810 (Core)

Virtual Machine Software Version: VirtualBox 6.0.10 r132072

Log in with administrator privileges
Create a user
```
adduser mytestssh
```
set password
```
passwd mytestssh
```
Give sudo privileges
```
gpasswd -a mytestssh wheel
```
-a: Add users to the target group
wheel: the meaning of the steering wheel, a special group of users in linux. Because the root user is very dangerous, so users will need administrator privileges to add to the group, so that the user can use the sudo command.
Under Administrator user query packet
```
lid -g wheel
```
If we can show the user to add, the above operations are successful.
Rsa key initialization
```
ssh-keygen -t rsa -b 4096 -C "[email protected]"
```
Instruction will be prompted to enter information, select the appropriate information to fill, can not fill the whole, has been the Enter skip setting.
Open ssh configuration file
```
vi /etc/ssh/sshd_config
```

Found in the file

#PermitRootLogin yes

PermitRootLogin yes

value	Whether to allow ssh landing	Login Method	shell command
yes	Yes	Unlimited	Unlimited
without-password	Yes	You can not log on with a password	Unlimited
forced-commands-only	Yes	You can only log in with a key	You can only have been authorized by the command
no	no

There are four values PermitRootLogin

save document

In front of the # removed.

Start ssh service
```
systemctl start sshd.service
```
Check the ssh service is started successfully
```
ps -e | grep sshd
```
```
ss -pltn | grip 22
```
It can be seen listening port
You can see the process, and then check port
Check whether the network is turned on
```
ip addr
```
Usually have more than one address, the name of the local lo card. If there is no other name card ip address, it is turned off.
Start card
```
nmtui
```
After this instruction, select the corresponding card, to activate a carriage return.
Virtual machines can not ping
原因可能是虚拟机网络设置的为NAT模式。如果继续使用NAT模式需要配置端口转发。也可用仅主机能访问的模式。
这里我们修改为桥接模式。然后检查网卡的IP是不是在同一网段。
ssh连接
```
ssh [email protected]
```
证书提示选择yes。密码输入正确后进入到虚拟机中。