Problem: Want to run command after SSH connected.
Solution: if you are using Ubuntu, enter:
echo 'command' >> ~/.bashrc
if you are using Centos, enter:
echo 'command' >> ~/.bash_profile
In my /etc/fail2ban/jail.conf file:
enabled = true port = ssh filter = sshd logpath = /var/log/auth.log bantime = -1 findtime = 10m maxretry = 5
So my Fail2ban should able to ban IP if the IP fails to attempt SSH 5 times within 10 minutes. But now Fail2ban not banning any IP
Solution: make sure Fail2ban service turned on
sudo fail2ban start sudo fail2ban-client start</code></pre>
Then make sure /var/log/auth.log file exist in order to log the record
Finally restart rsyslog
sudo /etc/init.d/rsyslog restart
Problem: Use SSH to connect the server as usual, then occur
The target server is re-format before, the authentication information has been changed. You have to delete the old authentication information in your computer first.
Solution:
Linux:
ssh-keygen -R (target server IP)
Windows:
Go to the host key directory, in my case the directory is “C:\Users\paulck.ssh”. Find the known_hosts file, delete the line that contains target server IP.
(target server IP) ecdsa-sha2-nistp256 (RSA key)