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Date: Fri, 18 May 2007 09:05:41 -0700
From: "Kian Mohageri" <kian.mohageri@gmail.com>
To: "Abdullah Ibn Hamad Al-Marri" <almarrie@gmail.com>
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References: <464D6880.2080306@vwsoft.com>
	<499c70c0705180656l4f601c1av45b6f9989792ccf1@mail.gmail.com>
Cc: Volker <volker@vwsoft.com>, freebsd-pf@freebsd.org
Subject: Re: Best way to decrease DDoS with pf.
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On 5/18/07, Abdullah Ibn Hamad Al-Marri <almarrie@gmail.com> wrote:
> Thank you for the tip.
>
> Here what I'm using which fixed the issue.
>
> pass in on $ext_if proto tcp from any to $ext_if port $tcp_services
> flags S/SA synproxy state
> pass in on $ext_if proto tcp from any to $ext_if port $tcp_services \
>         flags S/SA keep state \
>         (max-src-conn 30, max-src-conn-rate 30/3, \
>          overload <bruteforce> flush global)
> pass out proto tcp to any keep state
>
> Comments?

The first rule won't match anything (same criteria as second rule, and
last match wins with pf).  On the third rule, use 'flags S/SA' unless
you have a good reason not to.

Kian