cyrus pop3 question

[Andrew Morgan]

On Wed, 16 Apr 2008, Corey wrote:

> I just had an experience where my server was getting slammed with thousands
> of concurrent pop3 requests. This went on for over an hour before it finally
> ceased, at which point I was able to start cyrus again.
>
> Anyhow, what are some mechanisms to prevent this in the future?
>
> In the mean time, I'd like to know whether I can configure cyrus/pop3 to
> listen only on a specific interface rather than on all interfaces on the
> server, and if so - where do I configure that option?

You can modify cyrus.conf to bind a service entry to a particular IP 
address, like so:

   imap  cmd="imapd" listen="11.22.33.44:imap" prefork=1 maxchild=100

I don't think Cyrus has any mechanisms built-in to prevent a 
denial-of-service attack like you describe.  You can limit the impact on 
your machine by specifying a maxchild setting for your pop3 service.

 	Andy