https://www.cnblogs.com/netonline/p/7410586.html
89 ls /etc/ssh/ssh_host_rsa_key
90 cat /etc/ssh/ssh_host_rsa_key
91 sudo cat /etc/ssh/ssh_host_rsa_key
92 tail -f /var/log/auth.log
93 /usr/bin/sshd
94 /usr/sbin/sshd
95 ls /etc/ssh/
96 ll /etc/ssh
97 ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
98 sudo ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
99 ll /etc/ssh
100 sudo ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key
101 sudo ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key
102 ll
103 ll /etc/ssh
104 /usr/sbin/sshd
105 sudo /usr/sbin/sshd
106 ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key
107 sudo ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key
108 ll /etc/ssh
109 sudo /usr/sbin/sshd
ssh 连不上， 或putty出现 Network error:Software caused connection abort
原文：https://www.cnblogs.com/morganh/p/10636856.html