RSYNC over SSH backup using a different port - OS 6.1.2

Thanks to all who posted in this thread - this is exactly the same issue I was having; couldn't figure out why "test connection" worked fine but then after clicking "OK" it would fail.

I discovered something interesting (this doesn't help change the port but could be a potential workaround in certain cases). In my case I am trying to rsync to back up a remote directory on an Ubuntu 12.04 system running the csf/lfd firewall. Apparently with the CSF firewall, if you add an IP to the whitelist (csf.allow) then ALL ports can be accessed from that IP (even those that are not opened in the firewall). So you can add your home IP to the whitelist, open up port 22 in sshd_config, and the firewall will allow traffic on 22 from the whitelisted IPs while still blocking from everywhere else. So you'll still be able to hide port 22 from unknown IPs, which helps reduce the failed bruteforce attempts in the logs, but rsync from the ReadyNAS will work.

Ideally I'd still like a way to just specify my "preferred" SSH port directly in the web admin of the readyNAS, but this will work for now as my home IP almost never changes. I don't mind allowing sshd to listen on 22 as long as only a couple of IPs are allowed to see that port, and I still limit logins to specific usernames and require key-based authentication.