SSH: The server has disconnected with an error. Too many authentication failures

[Jasper_R]

Hi Guys,

I got the following error on two VSP 7200 switches. Got it solved on 1 switch by disabling and re-enabling SSH, but on the other switch, this doesn't work.

There are no active sessions, increasing the max-session allowed doesn't help, setting the timeout to 1 second to get "old" (there are none) session closed... But without any luck.

disabling rsa-auth did the trick on the last one, I could re-enable it after first ssh connections was successful.

Any one experience with this? Why does this happen?

Thanks!

Jasper

[Dilraj_Singh_Kh]

Great. Thanks for posting the solution.

[M_Nees · Accepted solution]

Today we can fix the issue with the excellent GTAC support.

Root Cause are empty SSH key files.

Deleting them and bouncing SSH will fix the problem.

delete .ssh/ssh_rsa.key
    Are you sure (y/n) ? y
delete .ssh/ssh_dss.key
    Are you sure (y/n) ? y

conf t

(config)#no boot config flags sshd
(config)#
(config)#
(config)#no ssh
(config)#
(config)#
(config)#boot config flags sshd
(config)#
(config)#ssh

(config)#sh log file tail
************************************************************************************
                Command Execution Time: Fri Jul 30 16:13:47 2021 CEST
************************************************************************************
1 2021-07-30T16:13:46.994+02:00 XXXXXX CP1 - 0x000d8635 - 00000000 GlobalRouter SSH INFO SSH Host key generation is completed successfully
1 2021-07-30T16:13:40.391+02:00 XXXXXX CP1 - 0x000d8634 - 00000000 GlobalRouter SSH INFO SSH Host Key generation is in progress. SSH connections will not be processed till the key generation completes
1 2021-07-30T16:13:40.390+02:00 XXXXXX CP1 - 0x0000461f - 00000000 GlobalRouter SNMP INFO SSH server enabled
1 2021-07-30T16:13:40.390+02:00 XXXXXX CP1 - 0x000d861c - 00000000 GlobalRouter SSH INFO SSH Server Enabled

[Dilraj_Singh_Kh]

Got it. So it’s better to be handled by the GTAC. This seems to have crossed the point where it can be answered on community.

DILRAJ

[M_Nees]

GTAC Case open since more than 1 week - 02418250