RE: [fw-wiz] CERT vulnerability note VU# 539363

From: Stephen Gill (gillsr@yahoo.com)
Date: 10/16/02


From: "Stephen Gill" <gillsr@yahoo.com>
To: "'Daniel Hartmeier'" <daniel@benzedrine.cx>
Date: Wed Oct 16 10:26:17 2002

Don't drop legitimate connections and try not to allow yourself to get
to the point where new connections can't be established either, assuming
you are well within your means of handling the load
(traffic/pps/memory/etc...).

The key is to make optimum use of those resources - in this case the
session table.

-- steve

-----Original Message-----
From: Daniel Hartmeier [mailto:daniel@benzedrine.cx]
Sent: Wednesday, October 16, 2002 8:54 AM
To: Stephen Gill
Cc: 'Mikael Olsson'; firewall-wizards@honor.icsalabs.com
Subject: Re: [fw-wiz] CERT vulnerability note VU# 539363

On Wed, Oct 16, 2002 at 08:20:09AM -0500, Stephen Gill wrote:

> In my opinion if a stateful firewall claims it can filter at rate X
> (64byte packets, etc...), it should be able to filter at that rate
under
> all conditions.

Obviously, for any X, when each packet is part of a TCP handshake, the
X/2 (or /3, depending on how you count) newly established connections
per
second will exhaust memory on the firewall after a certain amount of
time.

I don't think you meant 'be able to filter at that rate' to include
'dropping legitimate connections when running out of memory', did you?

> I'd like to learn some of the other methods being used for mitigation
> amongst vendors.

Yes, that's what I'd find most intersting to read in vendor statements
myself. :)

Daniel