Patrick Lists wrote:
Just a wild guess but could it be that fail2ban is trying to resolve all the IP addresses in it's database? Iirc there is a config option called use_dns. Try setting it to "no" or "warn".
Thanks for the suggestion. But I couldn't find any option like that anywhere below /etc/fail2ban in fail2ban-0.8.4-28.el6 .
More info on the wiki: http://www.fail2ban.org/wiki/index.php/Hostnames_or_IP_Addresses
Thanks very much. I'll see if changing the logfile has any effect, and if it doesn't I'll add "use_dns = no" to the config file.