Protect sendmail from DoS

[Devon Harding]

Is there some way of using something like IPTABLES to block if it sees a
certain amount of connections from a particualar IP? I know Ciphertrust
Ironmail does this.

On 11/1/05, Steven Jones <Steven.Jones at vuw.ac.nz> wrote:
>
> Sendmail has some protection in terms of load limiting, these are a bit
> high so you can set them lower so the server recovers sooner. This will
> save your server but in effect it allows DoS sooner.
>
> Possibly you do not understand what a DoS is. DoS is a function of your
> attacker overloading your network or server's capacity to handle network
> traffic sent at it.
>
> These days unless you are a big organisation with huge pipes, big
> multiple servers and deep pockets, and someone wants you dead, your
> dead.
>
> If someone wants to take your server out they can, it is simply a matter
> of logistics, they control 30 or 300 or 3000 or 30000 spam drones of
> hacked broadband connections and the volume these generate is amazing.
>
> I was Dos'd a while back, I was sent 5+gig of volume in 2~3 minutes, my
> 512k cable modem could not cope so in effect the DoS happened at the
> ISP's end of my pipe, totally outside of my control.
>
> Modern machines, even desktop ones should be able to handle a lot of
> mail, if you are having issues with DoS's then maybe it is something
> else.
>
> Regards
>
> Thing
>
>
>
> -----Original Message-----
> From: Devon Harding [mailto:devonharding at gmail.com]
> Sent: Wednesday, 2 November 2005 10:43 a.m.
> To: General Red Hat Linux discussion list
> Subject: Protect sendmail from DoS
>
> How can I protect my sendmail server against DoS attacks?
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