if you cannot logon to a linux machine and you got an error:
Check if the max failures in pam are reached:
root@debdev ~ # pam_tally --user root root@debdev ~ # pam_tally2 --user root
Another possiblity is that more authentification attempts/methods used then in sshd_config are allowed by
This could happend if too many ssh keys are loaded in ssh-agent. Try to reduce the keys, because each key is an authentification attempt. Or, if password authentication is allowed, add -o PubkeyAuthentication=no to the ssh command line under Linux or disable putty-agent usage in putty then only one attempt is made.