All of a sudden my ssh connection to server has been damaged. Here is what's happened: $ ssh -vvv -p <PORT> -l <USER> <HOST> OpenSSH_5.3p1 Debian-3ubuntu7, OpenSSL 0.9.8k 25 Mar 2009 debug1: Reading configuration data /home/khosrow/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to <HOST> [<IP>] port <PORT>. debug1: Connection established. debug1: identity file /home/khosrow/.ssh/identity type -1 debug1: identity file /home/khosrow/.ssh/id_rsa type -1 debug1: identity file /home/khosrow/.ssh/id_dsa type -1 ssh_exchange_identification: Connection closed by remote host I've recently updated the box with yum update and sshd got updated as well. I honestly don't know if this caused any damages or not. But it's prompted that /etc/ssh/sshd_config was stored as /etc/ssh/sshd_config.rpmnew which was quite normal. I've seen similar posts while googling, but almost all of them suggests that I should check /etc/hosts.allow and /etc/hosts.deny, which in my case, I can't. I can not connect to the box to see what's going on there. I rebooted the box, through web interface of server provider, and it even got worse. I'm now getting this: $ ssh -vvv -p <PORT> -l <USER> <HOST> OpenSSH_5.3p1 Debian-3ubuntu7, OpenSSL 0.9.8k 25 Mar 2009 debug1: Reading configuration data /home/khosrow/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to <HOST> [<IP>] <PORT>. debug1: connect to address <IP> port <PORT>: Connection refused ssh: connect to host <HOST> port <PORT>: Connection refused with both <CUSTOM_PORT> and default 22 ports. I would really appreciate if anyone could help me on this.