[Dovecot] limiting the per-time connections from one single IP address

[Uldis Pakuls]

suomi wrote:
> Hi every
> we had a havy pop3 attach yesterday morning: about 400'000 connects in 
> three hours from one single IP address within wandadoo.fr.
>
> the easiest way, to protect the dovecot server against such attacks 
> would be to limit the number of connections anyone can open from one 
> single IP address to the server in a certain time.
>
> this feature is available in newer versions of postfix, where i have 
> limited the number of SMTP connections possible from one single IP 
> address in one minute to three (3).
>
> thank you very much for any valid hint.
>
> suomi
There is no such feature in dovecot, but you can use iptables firewall
to do this.
An article with examples: http://www.debian-administration.org/articles/187

Uldis