i have had a lot of attacks on my vsftpd server with this format of rhost=rev.
fail2ban replies with
fail2ban.filter : WARNING Unable to find a corresponding IP address for rev.

i have nearly 4000 entries in my log for this morning and its still going on now

how do i ban this type of address ? i also get it occasionaly on my ssh server
i have read all the howto's and manual but must confess i dont really understand what i am reading
fail2ban works excellently apart from this