Re: [fw-wiz] Proverbial appliance vs software based firewall

From: Ryan M. Ferris (rferrisat_private)
Date: Tue Oct 15 2002 - 11:06:36 PDT

  • Next message: Ames, Neil: "RE: [fw-wiz] HOW TO Guide for testing firewalls?"

    I think what is missing here  from this discussion is a more serious debate
    on the inherent security differences between monolithic kernels and
    micro-kernels. Or perhaps real-time versus non-real time OS.
    
    I agree "Appliance" is a meaningless term - I've worked on three different
    appliances each with a different version of a different customized
    monolithic kernel OS (W2K SAK, RH Linux 7.0, OpenBSD). Someone could ship
    you embedded NT in a toaster oven and call it secure.
    
    What is not meaningless to security and function is kernel size,
    functionality, hardware access levels. Gigabit throughput is still best
    achieved by a switched bus architecture and custom ASICS or other real-time
    micro-kernel OS. The shared bus archictecture of even the fastest PCS and
    gigabit NICs will never be a match for dedicated hardware in processing
    traffic. There are many security applications where monolithic kernels
    /non-real time OS will just not be appropriate: You can tick them off in a
    big list but  imagine some critical scenarios:
    
    You are an NSA Analyst, monitoring traffic from multiple backbones that has
    be "muxed" or results from the parallel mirroring, spanning of many WDM
    optical switches - i.e. terabit amounts of information flow. The distributed
    systems needed to process such traffic on PC based sytems would be immense
    in number. You would probably opt for hardware based solutions as they would
    be more easily centralized.
    
    You are a major corporation (50K computer users) that wants a single  or
    minimum access points for all proxied or firewalled traffic. How could you
    use a PC based firewall for this purpose without using many firewalls?
    
    Part of your security requirement is the ability to handle multiple flooding
    type attacks (i.e. DOS, RDOS, DDOS, etc) with low risk of reboot or network
    congestion. What you opt for is gigabit switch architecture in your firewall
    not a shared bus PC architecture because you don't believe a Gigabit NIC on
    a shared bus archictecture can outperform an ASIC.
    
    Obviously, the question becomes more confusing when you start putting $ 16K
    NICS with their own OS and memory into a PC.
    
    Ryan M. Ferris
    rferrisat_private
    
    
    Ryan M. Ferris
    rferrisat_private
    
    
    
    ----- Original Message -----
    From: "Gary Flynn" <flynngnat_private>
    To: <firewall-wizardsat_private>
    Sent: Tuesday, October 15, 2002 9:27 AM
    Subject: Re: [fw-wiz] Proverbial appliance vs software based firewall
    
    
    > Anton Aylward wrote:
    > >
    > > On Tue, 2002-10-15 at 00:26, Jared Valentine wrote:
    > > >
    > > > While it is correct that all security comes down to "software" at some
    > > > point, I would argue that hardware is much more secure.  The
    difference
    > > > between the two is that the hardware manufacturer can build off of a
    trusted
    > > > base/OS.  They can look at the OS line by line and strip out
    everything not
    > > > essential for the operating of that firewall.
    >
    > So could some customers and they could do it with their specific
    > needs in mind.
    >
    > > I think that you "DON'T GET" Marcus's comment.
    > > Hardware in this sense is still software - embedded systems.
    > > Nothing in the Gartner paper contradicts that.
    >
    > Another way of looking at it is the difference between software
    > installed and configured by the vendor vs software installed
    > and configured by the customer...or maybe even proprietary vs
    > open source (sorry, couldn't resist).
    >
    > The effectiveness probably depends on the needs and capabilities
    > of the target market. I'm sure NSA would like the opportunity
    > to inspect and tune their own kernel and OS configuration while
    > a small company consisting mostly of web developers would rather
    > leave that chore to the vendor (and therefore trust them with
    > their security).
    >
    > One could make similar arguments either way for "appliance" web
    > servers, mail servers, or other turn-key systems.
    >
    > --
    > Gary Flynn
    > Security Engineer - Technical Services
    > James Madison University
    >
    > Please R.U.N.S.A.F.E.
    > http://www.jmu.edu/computing/runsafe
    > _______________________________________________
    > firewall-wizards mailing list
    > firewall-wizardsat_private
    > http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
    >
    
    _______________________________________________
    firewall-wizards mailing list
    firewall-wizardsat_private
    http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
    



    This archive was generated by hypermail 2b30 : Tue Oct 15 2002 - 12:47:56 PDT