One of my filers, running Data OnTAP 8.0.1, is immediately disconnecting any new ssh sessions. Authentication appears to be successful, but the session immediately drops once login has occurred. I have run "logout telnet," which returns "No active telnet session is present." I have also stopped and restarted ssh (via options ssh.enable), to no avail. I can't see anything in /etc/messages indicating a problem.
The bad news--- there will be an outage needed to resolve this issue. A reboot will fix the issue for some amount of time, but will not solve the root cause.
Upgrading to DOT 8.0.2+ will resolve the root cause of the issue.
Please note that I found the affected FAS will hang when you issue a reboot. (After DOT upgrade) This will also cause issues with cluster services which might affected the other head. (Why an NDU upgrade is not an option.) I had to login to the RLM/SP and physically powercyle the system for the reboot to actually move forward.
On additional note, while not the most secure, one can enable rsh (options rsh.enable on) to enable remote CLI management via RSH until such a time when an outage can be taken to fix SSH.