Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 6 Jun 2003 10:34:19 +0200
From:      "Kristian Rask" <krask@isupport.dk>
To:        <FreeBSD-net@FreeBSD.org>
Subject:   Choices for security
Message-ID:  <007601c32c06$9e242260$0a01a8c0@example.lan>

next in thread | raw e-mail | index | archive | help
Hi

In the ongoing saga a new question arises...

Presently the system is configured as follows

100 MBit WAN <--> FreeBSD Gateway <--> /28 DMZ-Net incl. 2 MS-IIS

ipfw is used to make basic protection for the Windows 2000 / IIS servers

ipfw is used kill setups from certain IP's to  DMZ/28 80,443

snort is listening for 80,443 setups on DMZ and logging to a MySQL =
server

A script at regular intervals asks MySql for identical src-ip's that =
returns more than LIMIT records.=20
The script then produces ipfw rules and inserts them. After this the =
script removes
all previously registered records from the database (so that the DB =
doesnt keep growing)
The script does a "ipfw show" and looks at the relevant records for nr =
of attempt and traffic amount. Based on this the script removes records =
from the rulesets when traffic drops to a certain level.=20
ipfw zeroes the relevant blocking rules so that a new period of traffic =
measuring and blocking can start


All of the above is being done at the moment and most of it is automatic =
by now.
However it seems to me to be overkill ....=20
Does anyone have an idea as to how one measures the IP traffic types in =
realtime ?=20

Another thing that has me wondering is something that would look kinda =
like route aggregation...
like... if i have more than X registrations of certified bad boys pr.  Y =
bits of network.. i would like
to detect this and recreate a network rule instead of a handfull of host =
rules.. eg.:
If i detect say 16+ rules belonging to the same /24 then i would like to =
detect this and replace the 16+ rules with 1 rule for the entire /26. =
The basic idea is to reduce the number of rules in the firewall for =
performance reasons.
Reviewing the last 3 days log files of ipfw rules shows a lot of cases =
where 10 - 20 machines came from a very narrow range of IP's.
I'm not asking anyone to invent the above... but if somebody has =
pointers to algorithms that will work well in the above scenario, i =
would be gratefull to know about them.


any and all input on the problem much appreciated..

Regards & TIA

Kristian



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?007601c32c06$9e242260$0a01a8c0>