Aug 18 11:13:22 stretch systemd[1]: Starting Fail2Ban Service...
Aug 18 11:13:23 stretch fail2ban-client[2062]: ERROR Found no accessible config files for 'filter.d/ssh' under /etc/fail2ban
Aug 18 11:13:23 stretch fail2ban-client[2062]: ERROR No section: 'Definition'
Aug 18 11:13:23 stretch fail2ban-client[2062]: ERROR No section: 'Definition'
Aug 18 11:13:23 stretch fail2ban-client[2062]: ERROR Unable to read the filter
Aug 18 11:13:23 stretch fail2ban-client[2062]: ERROR Errors in jail 'ssh'. Skipping...
Aug 18 11:13:23 stretch systemd[1]: fail2ban.service: Control process exited, code=exited status=255
Aug 18 11:13:23 stretch systemd[1]: Failed to start Fail2Ban Service.
Aug 18 11:13:23 stretch systemd[1]: fail2ban.service: Unit entered failed state.
Aug 18 11:13:23 stretch systemd[1]: fail2ban.service: Failed with result 'exit-code'.
Debian 9 is not supported (yet), but I'm willing to add support. Can you find out what the problem is? Maybe the name of the ssh filter. That was a problem in 16.04.
Hello,
Fail2ban doesn't work on debian 9 Stretch: