Connection throttling POP3.

Blake Hudson blake at
Mon May 21 16:36:34 EDT 2007

Andrew Morgan wrote:
> On Mon, 21 May 2007, Matthew Schumacher wrote:
>> List,
>> And this spammer is racking up a zillion processes which is killing my
>> machine.  I need a way to throttle this somehow where he is only allowed
>> one connection per IP at a time, or perhaps a way to ignore them after
>> so many invalid passwords.
>> Anyone know of a way to do this?
> You can use tcp-wrappers to block connections from that IP address
> entirely.  I believe there are also some solutions to monitor
> connections and automatically add IP addresses to the /etc/hosts.deny
> file, but I've never used them myself.
>     Andy

These types of threats are becoming more and more common and in reaction
awareness is increasing and more software seems to be implementing
mechanisms to cope. I would personally love to see Cyrus implement some
sort of connection limit or throttling per IP/network/user. The current
process limits do help ensure that one daemon does not make the machine
unusable, but does nothing to prevent a DoS attack.


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