Unfortunately, the SSH folks have removed support for the None cipher in later revisions so when we updated our ports, we lost that. We're going to create some other mechanism for "zero overhead replication" in 10 and then back-port it to 9.10, but that's not going to happen right away, so for now, just consider the None cipher dead and use one of the "cheaper" ciphers SSH offers. Sorry, but this one was just outside our control!