topic Re: SSH disconnects after 60mins - unexpectedly closed network connection in ONTAP Hardware

SSH disconnects after 60mins - unexpectedly closed network connection

GREG_WALKER — Thu, 05 Jun 2025 06:45:07 GMT

Hi all,

I've got an issue across all 4 of our v3240 filers (2 HA pairs). I am connecting to them via ssh, using public key encryption to authenticate to root account without any isue. I can work with the filers for exactly an hour, before I get booed out of my ssh session with "Server unexpectedly closed network connection". This happens with both Putty and Kitty ssh clients, and I have disabled all the autologout options i can find, and set all timeouts to over 60mins, but it is still disconnecting me. It happens regardless of activity within the session, sometimes I am in the middle of entering commands when it kicks me out.

toaster> options autologout

autologout.console.enable off (value might be overwritten in takeover)

autologout.console.timeout 540 (value might be overwritten in takeover)

autologout.telnet.enable off (value might be overwritten in takeover)

autologout.telnet.timeout 2880 (value might be overwritten in takeover)

toaster> options ssh

ssh.access *

ssh.enable on

ssh.idle.timeout 31536000

ssh.passwd_auth.enable on

ssh.port 22

ssh.pubkey_auth.enable on

ssh1.enable off

ssh2.enable on

Re: SSH disconnects after 60mins - unexpectedly closed network connection

aborzenkov — Mon, 26 Sep 2011 12:28:51 GMT

Do you have any firewall, NAT or similar device in the network path?

SSH disconnects after 60mins - unexpectedly closed network connection

GREG_WALKER — Mon, 26 Sep 2011 13:04:27 GMT

No, there is a WAN link between myself and one pair, but I am in the office next to one datacentre with an affected pair. There's no firewall configured on my workstation either. I'm certain it's the filers that are disconnecting me, as I often open up 4 KiTTY sessions to each of the filers one after another. It takes me a few seconds of clicking to launch each session in turn, and one hour later, I can see the disconnect messages appear with the same few secconds between each session.

Re: SSH disconnects after 60mins - unexpectedly closed network connection

RAESIDEPAUL — Wed, 16 Nov 2011 15:58:30 GMT

open putty > got to change settings > connection > ssh > kex change "Max Minutes before rekey (0 for no limit)" to 0 for no limit. I bet yours is set to 60 right now...

Re: SSH disconnects after 60mins - unexpectedly closed network connection

TINKERDUDE1 — Sat, 14 Jan 2012 07:59:44 GMT

I had the exact same problem. Drove me nuts for months. But RAESIDEPAUL got it right (putty ssh/kex timeout config) and all is well now. RAESIDEPAUL should get credit for a correct answer.

Re: SSH disconnects after 60mins - unexpectedly closed network connection

TONY_BARNETT — Fri, 07 Sep 2012 15:46:18 GMT

I made this change in putty and still get disconnected exactly 60 minutes after login.

filer2> options autologout

autologout.console.enable on (value might be overwritten in takeover)

autologout.console.timeout 300 (value might be overwritten in takeover)

autologout.telnet.enable on (value might be overwritten in takeover)

autologout.telnet.timeout 300 (value might be overwritten in takeover)

filer2> options ssh

ssh.access *

ssh.enable on

ssh.idle.timeout 0

ssh.passwd_auth.enable on

ssh.port 22

ssh.pubkey_auth.enable on

ssh1.enable off

ssh2.enable on

Re: SSH disconnects after 60mins - unexpectedly closed network connection

TONY_BARNETT — Thu, 13 Sep 2012 19:54:59 GMT

Disregard. I made a boo-boo. This did fix my issue also.

Thanks!

Re: SSH disconnects after 60mins - unexpectedly closed network connection

GVM666GVM — Tue, 16 Oct 2012 09:29:59 GMT

RAESIDEPAUL

You are totally right fixed my problem as well!

GREG.WALKER: please mark this thread as solved if it was for you.

Re: SSH disconnects after 60mins - unexpectedly closed network connection

NICOLAS_MELAY — Mon, 06 May 2013 15:15:51 GMT

As could be guessed from its name, fiddling with rekey settings is not a good idea security wise.

You should NOT do this.

http://the.earth.li/~sgtatham/putty/0.58/htmldoc/Chapter4.html#config-ssh-kex-rekey

If you change it anyway, do so on a custom saved session, not in the default PuTTY session.

The real fix for this problem lies in NetApp's hands: ONTAP's SSH server needs rekey support.

Edit:

The NetApp bug has actually been accounted for by PuTTY's developper, and there's a workaround.

You just need to enable it in the "bugs" page.

That's much better than totally disabling rekeying.

Have been using it for the last few days, so far so good.

Re: SSH disconnects after 60mins - unexpectedly closed network connection

XQ10907RS — Mon, 04 Aug 2014 09:26:45 GMT

this workaround works for me,thanks!

Re: SSH disconnects after 60mins - unexpectedly closed network connection

koumoun_nik — Thu, 28 May 2015 17:03:50 GMT

anks a lot this was the proper answer, it solved my problem as well.