Sometimes we can not login VPS via SSH because of wrong configured firewall like iptables or SSH service or some other mistake. VPS control panel shows online status but can't access SSH. How to Fix it yourself? A serial console will act as if you have a monitor plugged directly into your VPS and can be used to watch it's startup process or trouble shoot errors.  It is especially useful if you accidentally lock yourself out of your VPS. Below will show you how to access your ComfortVPS Serial Console.

1. Login your client area and go into VPS control page.

   You can find your VPS at menu "Service"->"My Servers" after login ComfortVPS client area. 

   Directly Link: http://www.comfortvps.com/clients/clientarea.php?action=products

   Then click the "View Details" to see the bandwidth usage and control your vps such as reboot / shutdown.

   

2. Click "Serial Console" button:
   

3. Create a auto-timeout session for ComfortVPS Serial Console. eg. Below screenshot image created a 3 hours session.
   

4. A JAVA app lunched for SSH serial console. You will need install JAVA if you don't have it. Then you will see a temp console password.  There is no need to write this password down as it will only be used this time. You can copy this password first. 

   NOTE: Depending on your java settings you may receive a java warning that asks: "Block potentially unsafe components from being run?".  If this warning message appears be sure to hit "Yes".  Answering "No" will cause a java error and you will have to close the window and start over.
    

5. Finally a login prompt will pop up.  You will not recognize the username, it is a special console username and should not be changed.  Paste or input your console password from the step above and hit "OK" to login:
   

6. Input username and password of your VPS to login.  Note: the password is not the serial console temp password, it should be your VPS root password.
   

7. You can use any command you like after login, like a SSH client software.
   You can shutdown iptables: service iptables stop  and restart sshd: service sshd restart  first, then try login via ssh client to see if ssh works again.