topic RE: How do I regain ssh/console access to Enterasys S6? in ExtremeSwitching (EOS)

How do I regain ssh/console access to Enterasys S6?

Clovens_Rateau — Wed, 15 Jul 2015 19:58:00 GMT

Hi, I lost console and ssh access to the an Enterasys S6. I keep on getting this error message "Master Console in use". Someone suggested that I press the enter key multiple times and the error message would go away, that didn't work. Have any of you experience something like this? I would not want to reboot the device, it plays a really important role in the network.

RE: How do I regain ssh/console access to Enterasys S6?

Paul_Poyant — Wed, 15 Jul 2015 20:39:00 GMT

Under discussion is a "

code:

Master console in use on another board.

" message in response to an attempted console session.

This has been reported on a S-Series bonded system in which a console session was already open on one chassis and a fresh session was attempted on the second. The resolution there was to close out the initial console session on the first chassis.

It's also been observed on a S-Series system - occurring for unknown reason - and resolved by rebooting the system.

For the N-Series this can occur in apparent response to some improperly interpreted keystrokes during a management session. The resolution there is to issue a "

code:

Ctrl-D

" key sequence.

If none of that is helpful in this particular situation, then I suggest you open a GTAC Support case for more directed assistance.

RE: How do I regain ssh/console access to Enterasys S6?

Luke_French — Wed, 15 Jul 2015 20:39:00 GMT

If you have lost snmp and console access as well then the problem may be related to the one documented in this article.

Title: S-Series no longer responding to SSH/SNMP/Console
Article Link: http://gtacknowledge.extremenetworks.com/articles/Solution/S4-no-longer-responding-to-SSH-SNMP-Conso...

RE: How do I regain ssh/console access to Enterasys S6?

Mike_D — Thu, 16 Jul 2015 22:53:00 GMT

Hello,

Device console/remote console management issues can be a little tricky.
In addition to the previous answers, I'll add the following - hope it helps.

If switch management is unresponsive due to a temporary CPU starvation condition, use local console and hit ctrl-d (similarly noted by Paul) a few times to request high priority login. note - this approach does not work via ssh or telnet, you need a direct connection.
The elevated priority access method allows issue management under stress/fault conditions such as a DOS attack or network loop.

one other item comes to mind: If all ssh access hangs (see release note fixes), a reset of the currently elected system management blade - identified by lit mgmt led - is normally enough to free these stuck sessions.

regards
Mike

RE: How do I regain ssh/console access to Enterasys S6?

Clovens_Rateau — Thu, 16 Jul 2015 23:06:00 GMT

Hi All,

Thanks for your suggestions. I had to reboot the S6.