ssh is ok, but connection refused when trying to rsync, why?

Solution 1:

Try verbose mode in rsync by adding -vvv to see where it is failing.

Are you using a very old version of rsync that doesn't default to using ssh (older than 2.6.0)? If so, try adding -e ssh to force ssh mode.

Please edit your question and paste your debug output and the exact rsync command line you are trying to run.

Solution 2:

You say:

The only connection allowed is ssh

When trying to use the rsync daemon as opposed to rsync over ssh you need to open tcp port 873 and ensure that the rsyncd is running on the remote machine.

In this case I suspect you actually want to do rsync over ssh in which case changing the double :: to a single : may well be enough to achieve this:

rsync -v athens:/disk3/nicolas/scripts/ .

Something like the above might do it, you'll need a single : and to specify a valid path.