Hi everybody,
Thanks very much for the kind advises given yesterday and today.
I have now implemented the blocklist on
* http://list.blocklist.de/lists/all.txt
using the scripts here:
* https://forum.blocklist.de/viewtopic.php?f=11&t=84#
(a combi of bash and php)
For now, my server appears to handle that approach (with the seperate
iptables rules) quite nicely. But I will keep the ipset solution in mind.
Anyone aware of other blocklists that are worth bocking? Because the
list.blocklist.de/lists/all.txt blocks some, but not anywhere near all.
I now know how to block large lists of ips, so if anyone has additional
lists to block?
MJ
On 07/19/2017 12:42 PM, Dave wrote:
On 19/07/2017 11:23, mj wrote:
Hi Robert,
On 07/18/2017 11:43 PM, Robert Schetterer wrote:
i guess not, but typical bots arent using ssl, check it
however fail2ban sometimes is to slow
I have configured dovecot with
auth_failure_delay = 10 secs
I hope that before the 10 sec are over, dovecot will have logged about the
failed login attempt, and fail2ban will have blocked the ip by then.
I realise this is orthogonal to dovecot, but if you are attempting to block a
very large number of IPs, it is more efficient to use a single ipset than
thousands of iptables rules:
For example, given a single firewall rule:
iptables -A INPUT -p tcp --dport 143 -m set --match-set imap-bl src -j DROP
/etc/fail2ban/jail.conf:
[imap]
...
action = ipset[name=imap-bl]
/etc/fail2ban/action.d/ipset.conf:
[Definition]
# fail2ban tracks, so we dont use ipset timeout
actionstart = /usr/sbin/ipset -exist create <name> hash:ip maxelem 131072
actionstop = /usr/sbin/ipset -exist flush <name>
actioncheck =
actionban = /usr/sbin/ipset -exist add <name> <ip>
actionunban = /usr/sbin/ipset -exist del <name> <ip>
You may have to ensure the ipset is present before referencing it in iptables,
for example, Redhat-alikes will have an ipset init script that operates in
exactly the same way as iptables (start/stop/save), with the configuration
stored under /etc/sysconfig/ipset:
create imap-bl hash:ip family inet hashsize 1024 maxelem 131072
chkconfig ipset on
service ipset start
(create iptables rules, ipset created on boot prior to iptables, other distros
likely have similar configuration)
I've found that the slowest component tends to be fail2ban itself, which has
difficulty tracking a large number of IPs or even tailing sufficiently busy
logfiles.
