When enabled sshd jail i see Starting fail2ban: ERROR NOK: ("Failed to initialize any backend for Jail 'sshd'",)
ERROR NOK: ('sshd',)
In logs :
ERROR Backend 'systemd' failed to initialize due to No module named systemd
ERROR Failed to initialize any backend for Jail 'sshd'
Centos 6.7 no have systemd module . CentOS 6.7, python 2.6
Just replace in you jail config backend to auto From
[sshd]
enabled = true
filter = sshd
port = ssh
logpath = %(sshd_log)s
backend = %(sshd_backend)s
To
[sshd]
enabled = true
filter = sshd
port = ssh
logpath = %(sshd_log)s
backend = auto
And restart service service fail2ban restart