Home page logo

basics logo Security Basics mailing list archives

Re: Recommending an IDS system
From: "Andy Cuff" <lists () securitywizardry com>
Date: Sat, 28 Feb 2004 10:20:37 -0000

Hi Mat,
I was faced with the same dilemma some years back, my site below details the
various technologies you can bring to bear.  I also wrote an article for
SecurityFocus regarding deploying IDS from a vendor neutral standpoint

I'd suggest starting simply and building up but always keep the defence in
depth end goal in sight.  Also, don't forget that in addition to detecting
attacks you have to react to them also.  If you need further advice offlist
don't hesitate to ask.

Finally, if you go down the Network IPS route there are 2 main varieties;
rate based and content based, I refer to the former as Attack Mitigation
Systems  they fill an important role but IMHO are not IPS.  Ideally you
should have both varieties.   There are some products that claim to do both,
but .....

take care
Talisker Security Tools Directory
----- Original Message ----- 
From: "Matthew MacAulay" <matthew.macaulay () cobweb co uk>
To: <security-basics () securityfocus com>
Sent: Thursday, February 26, 2004 12:36 PM
Subject: Recommending an IDS system


I have been tasked with looking at and recommending an IDS system for my

I have been looking at open source products (Snort) which seems to be a
very good system with a lot of community support. My problem is we are
an ASP. We want connections to be able to reach our systems for the
services we provide. I want to be able to monitor over 100 internet
facing servers (behind Firewalls and load balancers) and alert / and
possibly block non normal traffic / detected attack signatures.

After doing some reading into different methods IDS v IPS, Host v
Network, I favour a combination, we have at anyone time up to 50,000
concurrent connections to our systems so I have a problem of scale. One
Snort box is just not going to cut it!

Looking at how I can "tap" into the network traffic has been partially
solved by using IDSVLANS which is supported by our Switch hardware.
(Nortel 8600) So an IDSVLAN could be setup for each of our existing
VLANS and a couple of load balanced IDS boxes per IDSVLAN to alert to a
central server to produce reports / alert / wake people up.... Sounds

Though I have not looked at it in as much detail as network based IDS, I
expect I can get a hosts based IDS to also alert (SNMP or what ever) to
a central server to again produce reports / alerts / wake people up.

I am interested to here what systems you use to do IDS / IPS. Do you
have in place IDS systems for platforms of a larger or similar scale? I
would like to here from people have who have faced similar challenges.

Questions I keep asking myself:

Am I trying to do too much, should I just concentrate on host based IDS?

Is network based IDS the right way to go?
Or am I right in trying to do both?
Should I be using an open source product to do ID?
Are there commercial products which can do what I want?

Your thoughts, recommendations and pointers to further reading are



The information in this email is confidential and may be legally
privileged. It is intended solely for the addressee. Access to
this email by anyone else is unauthorised. If you are not the
intended recipient, any disclosure, copying, distribution or any
action taken or omitted to be taken in reliance on it, is
prohibited and may be unlawful. If you have received this
communication in error please return it to the sender, then
delete and destroy any copies of it.



  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]