本机sshd服务开启但是其他机器不能登陆

问题现象：

发现本机sshd服务开启但是其他机器不能登陆

查看sshd服务

[root@localhost ~]# systemctl status sshd.service
● sshd.service - OpenSSH server daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun -- :: PDT; 21min ago
     Docs: man:sshd()
           man:sshd_config()
  Process:  ExecStart=/usr/sbin/sshd $OPTIONS (code=exited, status=/SUCCESS)
 Main PID:  (sshd)
   CGroup: /system.slice/sshd.service
           └─ /usr/sbin/sshd

Jun  :: localhost.localdomain sshd[]: error: bad permissions: ignore key: /etc/ssh/ssh_host_ecdsa_key
Jun  :: localhost.localdomain sshd[]: error: Could not load host key: /etc/ssh/ssh_host_ecdsa_key
Jun  :: localhost.localdomain sshd[]: error: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Jun  :: localhost.localdomain sshd[]: error: @         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
Jun  :: localhost.localdomain sshd[]: error: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Jun  :: localhost.localdomain sshd[]: error: Permissions  for '/etc/ssh/ssh_host_ed25519_key' are too open.
Jun  :: localhost.localdomain sshd[]: error: It is required that your private key files are NOT accessible by others.
Jun  :: localhost.localdomain sshd[]: error: This private key will be ignored.
Jun  :: localhost.localdomain sshd[]: error: bad permissions: ignore key: /etc/ssh/ssh_host_ed25519_key
Jun  :: localhost.localdomain sshd[]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key

解决方法：可以很容易看出来这是因为ssh服务的配置文件的访问权限有问题，配置文件路径为/etc/ssh，将这些文件的权限修改为如下即可:

[root@localhost ssh]# ls -al
total
drwxr-xr-x.    root root         Jun  : .
drwxr-xr-x.  root root        Jun  : ..
-rw-r--r--.    root root      Nov    moduli
-rw-r--r--.    root root        Nov    ssh_config
-rw-r--r--     root root        Jun  : sshd_config
-rw-------.    root ssh_keys     May  : ssh_host_ecdsa_key
-rw-r--r--.    root root         May  : ssh_host_ecdsa_key.pub
-rw-------.    root ssh_keys     May  : ssh_host_ed25519_key
-rw-r--r--.    root root          May  : ssh_host_ed25519_key.pub
-rw-------.    root ssh_keys    May  : ssh_host_rsa_key
-rw-r--r--.    root root         May  : ssh_host_rsa_key.pub
[root@localhost ssh]#