[root(0)@sys11 09:20:29 /home/work/Code_release/bj]# scp ./release.sh  root@192.168.161.151:/Users/a2014102/Downloads
ssh: connect to host 192.168.161.151 port 22: Connection refused
lost connection

Solution:
One possible reason is that because the ssh server daemon, or sshd, is not loaded and running on localhost, so any attempt to ssh connect to localhost would fail. I check to see whether ssh and sshd are running by typing the following command:

1. $ ps aux | grep ssh  

2. # Result: bunch of lines, but none of them is about "sshd", only one line is about "ssh"  

Result is, I only see ssh running, but not sshd. So I know ssh server daemon is probably not started yet.

First, I verify that I have installed the package “openssh-server” on my fedora box.

Then I check the status of sshd service:

You may not have OpenSSH completely installed. Type this in terminal:

1. sudo apt-get install openssh-client  

2. sudo apt-get install openssh-server  

Another problem that you could have is that your firewall could be blocking the ssh connection. I use Firewall Configuration to manage my ports and firewall.

to restart it type

1. sudo /etc/init.d/ssh restart  

to stop it type

1. sudo /etc/init.d/ssh stop  

to start it type

1. sudo /etc/init.d/ssh start  

 以下是主要的关键步骤：

OpenSSH server on Mac OS X

OpenSSH server is part of Mac OS X and you don‘t need to install any additional package.

To enable the OpenSSH server of Mac OS X, open System Preferences:

Click on sharing and enable Remote Login:

This will start up OpenSSH server automatically.

直接关掉就保存了，因为mac是时时保存的。