I have been running fail2ban on my server for a while without any problems but have recently seen fail2ban restart randomly. After some looking in my logs I noticed that the restarts occur when ever someone gets banned.
So every time someone gets banned the fail2ban server restarts.
Here are a couple of logs.
2012-03-23 00:58:39,025 fail2ban.actions: WARNING [dovecot] Ban xx.xx.xx.xx (ip removed)
What I have been able to find out is that the fail2ban bans the IP and then it restarts and the only error I can find is.
2012-03-23 00:58:39,025 modprobe: FATAL: Module ip_tables not found.
Iptables is present and running - and I can issue any commands without iptables failing or fail2ban crashing.
Please let me know if you have any idea and if you would need the fail2ban config files
Centos 5.8 Fail2ban 0.8.2 Iptables 1.3.5