Putty connection to CentOS connection is denied

First check whether the SSHD service is enabled

Enter terminal input #ssh localhost

If prompted: Ssh:connect to host localhost port 22:connection refused error

No need to worry about it, no starting sshd service for the sake of

Install sshd command: #yum install Openssh-server

Open after installation: #/etc/init.d/sshd start or service sshd start

In case the connection does not go up at this time, firewall open 22 port can

#/sbin/iptables-i input-p TCP--dport 22-j ACCEPT

Then save it, be sure to save it first
#/etc/rc.d/init.d/iptables Save

#重启防火墙才生效
/etc/init.d/iptables restart

#查看防火墙信息
/etc/init.d/iptables status

If not, it should be an SSH configuration file problem/etc/ssh/sshd_config

Vi/etc/ssh/sshd_config

Add (I was empty before adding)

Passwordauthentication Yes (allows login with password)
Permitemptypasswords Yes (no blank password to log in)

Permitrootlogin Yes (allows the root user to log in using SSH)

Not yet......

The security configuration of the CentOS system default system leads to some puzzling problems, such as that SELinux was originally used for the security subsystem's permission control, but it is not possible to find a lot of restrictions, we can use the following methods to quickly close selinux.

/usr/sbin/setenforce 0 Close SELinux immediately

/usr/sbin/setenforce 1 Enable SELINUX now

Add to system default boot inside

echo "/usr/sbin/setenforce 0" >>/etc/rc.local

This allows us to quickly shut down when we don't need to open selinux in the CentOS system, and to turn it on when needed.

Putty connection to CentOS connection is denied