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That rip=18.104.22.168 is a known offender, see http://www.bizimbal.com/odb/details.html?id=900596
I have seen a suggestion to use the route command to block the offending IP: route add -host 22.214.171.124 reject
However reading the man page about 'route', it says reject is not to be used for firewalling.
I am wondering if this would be correct? route add -host 126.96.36.199 null
Alternatively, if I put this in iptables INPUT: DROP all -- 188.8.131.52 anywhere
will it keep that marauder away from Dovecot?
Last edited by cnmoore; 03-27-2011 at 01:27 PM.
Reason: Added iptables question
I have assumed that when there are hundreds of "pop3-login: Disconnected (auth failed, .."
the marauder is trying all different user names/passwords and that if they succeed in breaking into an account they can then use it to send out spam.
We are actually very safe as there are only two email accounts on the server and both have 17 character randomly generated passwords. But the trash clutters my logwatch and of course uses resources.
Can't really tell yet if the iptables thingy is working as pop-3 login hammering doesn't happen every day. There is something new in the logwatch report, though. Masses of these:
--------------------- Dovecot Begin ------------------------
Logged out bytes=102/1952: 1 Time(s)
Logged out bytes=114/1395: 3 Time(s)
Logged out bytes=117/1401: 2 Time(s)
Logged out bytes=132/1395: 2 Time(s)
Logged out bytes=132/1398: 1 Time(s)
Logged out bytes=135/1401: 4 Time(s) ...
I have no idea what those are or how to interpret them.
Last edited by cnmoore; 03-28-2011 at 02:57 PM.
Reason: removed stuff I figured out