IDS mailing list archives

RE: Intrusion prevention and dDos protection


From: kgeorgiades () toplayer com
Date: Thu, 28 Aug 2003 09:12:18 -0400

An appliance that handles IPS with excellent DDos functionality is the Top
Layer AM IPS

http://www.toplayer.com/content/products/intrusion_detection/attack_mitigato
r.jsp

It fits perfectly in environments with slow firewall.

There are hundreds of customers using it.

Note: I work for Top Layer.

Ken Georgiades

-----Original Message-----
From: Paul Benedek [mailto:paul.benedek () excis co uk]
Sent: Tuesday, August 26, 2003 12:19 PM
To: 'Rob Shein'; 'Darren Windham'; focus-ids () securityfocus com
Subject: RE: Intrusion prevention and dDos protection


Rob,

You have a point.  There are some considerations that may be pertinent with
regard to this issue.  Firstly as you point out, there are no definitive
solutions.  If there were any definitive solutions they would almost
certainly rely on good design practices and this is what is being advocated
here.  Any connection to the Internet should include liaison and design with
the ISP.  Most ISP's will allow rate limiting at the edge within their
domain if you request it.  Similarly if you rate limit at your edge, you
control the traffic passing across the edge into your realm. 

In terms of dropping traffic on the edge, again a DDOS can overwhelm the
resources dealing with incoming and outgoing traffic, however you can
control the switching of network traffic and the amount of CPU interrupts
called on most routers.  By being granular in your approach and by black
holing non essential service specific traffic, you are less likely to
overwhelm your own critical network resources such as firewalls and routers.
This is done by specifying ports, disallowing fragmented traffic and non
essential traffic like ICMP.  

Sadly my flawed assumptions require an in depth security solution that
involves many different parties.  It is not ideal and only offers a limited
defence against a DDOS.  The point being that this solution may be better
than nothing and if it can prevent you being hit by at least one DDOS, it
may be worth considering.

Regards


Paul Benedek
Director
Excis Networks Limited
http://www.excis.co.uk











-----Original Message-----
From: Rob Shein [mailto:shoten () starpower net] 
Sent: 26 August 2003 14:31
To: 'Paul Benedek'; 'Darren Windham'; focus-ids () securityfocus com
Subject: RE: Intrusion prevention and dDos protection

Even this is predicated upon a critical and flawed assumption, being that
the pipe leading to your border router has more bandwidth than the pipe
leading from it.  This is not the case; any rate limiting cannot be done by
you and must be done by the ISP itself.  While this is possible, it is out
of the realm of product-based solutions and goes more towards cooperative
efforts with the ISP, which is the basis of all DDOS defense anyways.

Denying types of traffic at your border will be useless; that's like the
highly aware security guard at the front desk.  The bad people aren't
getting past him, but it's already too late for that to matter.

-----Original Message-----
From: Paul Benedek [mailto:paul.benedek () excis co uk] 
Sent: Tuesday, August 26, 2003 5:18 AM
To: 'Rob Shein'; 'Darren Windham'; focus-ids () securityfocus com
Subject: RE: Intrusion prevention and dDos protection


Hi,

Although the analogy is correct and that a well planned DDos 
attack can cause you to loose services, there are several 
things that you can do to limit the chances of success.

Firstly at your ISP edge you can introduce rate limiting.  By 
limiting the amount of certain types of traffic, you can 
allow for legitimate traffic to pass.  For example if you 
have a 2 meg pipe, you can limit the amount of UDP to half a 
meg, tcp on port 80 and 443 to 1 meg and half a meg for other 
traffic.  If the traffic exceeds these values, you can force 
the traffic to be dropped.

If you are explicit with the traffic you are allowing, you 
can further limit the effects of a DDOS attack.  For example 
you can deny all fragmented traffic and ICMP.  You can 
specify the hosts and ports that need connectivity with a 
high degree of granularity and drop all other traffic. 
Furthermore if you implement RFC2827 filtering you can limit 
the chances of being used as a DDOS engine yourself.

In most cases a well thought out DMZ and ISP edge can reduce 
the chances of a success, however as pointed out, you will 
not get total protection.  You may however be able to keep 
critical services operational at the time of a DDOS attack.


Regards,

Paul Benedek
Director 
Excis Networks Limited
http://www.excis.co.uk




-----Original Message-----
From: Rob Shein [mailto:shoten () starpower net] 
Sent: 23 August 2003 18:26
To: 'Darren Windham'; focus-ids () securityfocus com
Subject: RE: Intrusion prevention and dDos protection

I would hasten to point out that there isn't anything you can 
buy that will give you DDos protection.  While a firewall/IPS 
is like a security guard at the entrance to a building to 
keep bad people out, a DDos attack is like so many bad people 
trying to get into the building that they choke the streets 
leading up to it; nothing you can put in your building will 
deal with that congestion or prevent it.

-----Original Message-----
From: Darren Windham [mailto:dwindham () dallastelco org]
Sent: Thursday, August 21, 2003 10:17 AM
To: focus-ids () securityfocus com
Subject: Intrusion prevention and dDos protection


I recently had the chance to meet with the guys over at
Melior and talk about their iSecure platform.  Has anyone 
else taken a look at it?  I was pleasantly suprised at its 
performance.  I ran most of the common scanners on both Linux 
and Windows platforms and had no such luck with it.  I can 
only hope that more products like this make it to the 
mainstream marketplace.  If you are looking for a IPS/dDos 
prevention I'd make sure you take a good look at these guys.  

I'd love to hear feedback from others who have looked at this
or other similar products.

Check them out at http://www.meliorinc.com

Regards,

Darren Windham
Network Administrator, Dallas Telco FCU 
email: dwindham () dallastelco org <mailto:dwindham () dallastelco org> 




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--------------------------------------------------------------
-------------
Attend Black Hat Briefings & Training Federal, September 
29-30 (Training), October 1-2 (Briefings) in Tysons Corner, 
VA; the worldÂ's premier 
technical IT security event.  Modeled after the famous Black 
Hat event in 
Las Vegas! 6 tracks, 12 training sessions, top speakers and 
sponsors.  
Symanetc is the Diamond sponsor.  Early-bird registration 
ends September 6
Visit: www.blackhat.com
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---------------------------------------------------------------------------
Attend Black Hat Briefings & Training Federal, September 29-30 (Training),
October 1-2 (Briefings) in Tysons Corner, VA; the worldÂ's premier 
technical IT security event.  Modeled after the famous Black Hat event in 
Las Vegas! 6 tracks, 12 training sessions, top speakers and sponsors.  
Symanetc is the Diamond sponsor.  Early-bird registration ends September 6
Visit: www.blackhat.com
---------------------------------------------------------------------------

---------------------------------------------------------------------------
Attend Black Hat Briefings & Training Federal, September 29-30 (Training), October 1-2 (Briefings) in Tysons Corner, 
VA; the world’s premier 
technical IT security event.  Modeled after the famous Black Hat event in 
Las Vegas! 6 tracks, 12 training sessions, top speakers and sponsors.  
Symanetc is the Diamond sponsor.  Early-bird registration ends September 6 Visit: www.blackhat.com
---------------------------------------------------------------------------


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