Hi Paul,
I went into this on the Focus-IDS mailing list a month or so ago.
Basically, I believe IPS to be more of a threat to (or the future of)
firewalls. Network intrusion prevention devices sit in-line and
provide permit/deny access control for packet streams based on whether
or not they're attacks. Presumably it would be relatively easy as a
subset of functionality to add stateful packet filtering that's just as
good or better than any existing firewalling mechanisms. Netscreen and
Checkpoint have figured this out which is why you see them making
aggressive moves in the IPS space. Intrusion detection devices have a
VERY different role in the network security hierarchy, they provide
*awareness* of what's happening on your network, verification of policy
compliance and detection of potential threats and anomalies.
Let me lay out two scenarios that illustrate why intrusion prevention
!= intrusion detection and why it's unlikely that IPS will ever replace
IDS (and how everyone who's trying to tell you it will is trying to
sell you something):
1) IPS devices only guard the peering points (at best) of the network.
In the case of an attack between hosts on the same broadcast network
(inside the peering point) you have absolutely no coverage from the
IPS. In that case you'll need to have an IDS to tell you what's going
on. For example, someone in engineering decides to give him self a
raise by hacking into the accounting department and making it so, your
IPS has no visibility into this traffic so it's quite worthless. Your
IDS can see this traffic, however, and collect the relevant information
for detection/enforcement of policy and evidence for law enforcement.
2) No IPS is going to be perfect, so attacks are going to slip through
them. It can be attacks that they don't know about (new buffer
overflows, etc) or even traffic that's legitimate but hostile in your
environment, like non-anonymous logins to your anonymous FTP server.
If an attack gets by an IDS, how will you know? You better have a
pretty good IDS to tell you, that's how.
There are several other things I could highlight, but I think this
illustrates the point pretty well and it's Friday and late and I feel
like going home. :)
-Marty
On Friday, December 13, 2002, at 12:30 PM, Sheahan, Paul (PCLN-NW)
wrote:
I attended Infosecurity 2002 yesterday and there was much talk about
intrusion detection going away, and intrusion prevention replacing it.
Does
anyone know if there are any plans to include intrusion prevention
functionality into Snort in the future?
Thanks,
Paul Sheahan
Manager of Information Security
Priceline.com
paul.sheahan@priceline.com
-------------------------------------------------------
This sf.net email is sponsored by:
With Great Power, Comes Great Responsibility
Learn to use your power at OSDN's High Performance Computing Channel
http://hpc.devchannel.org/
_______________________________________________
Snort-users mailing list
Snort-users@lists.sourceforge.net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users
--
Martin Roesch - Founder/CTO, Sourcefire Inc. - (410)290-1616
Sourcefire: Snort-based Enterprise Intrusion Detection Infrastructure
roesch@sourcefire.com -
http://www.sourcefire.com
Snort: Open Source Network IDS -
http://www.snort.org
-------------------------------------------------------
This sf.net email is sponsored by:
With Great Power, Comes Great Responsibility
Learn to use your power at OSDN's High Performance Computing Channel
http://hpc.devchannel.org/
_______________________________________________
Snort-users mailing list
Snort-users@lists.sourceforge.net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users