nanog mailing list archives

Re: misunderstanding scale


From: William Herrin <bill () herrin us>
Date: Mon, 24 Mar 2014 13:37:06 -0400

On Mon, Mar 24, 2014 at 9:25 AM, Joe Greco <jgreco () ns sol net> wrote:
I say this with the utmost respect, but you must understand the
principle of defense in depth in order to make competent security
decisions for your organization. Smart people disagree on the details
but the principle is not only iron clad, it applies to all forms of
security, not just IP network security.

The problem here is that what's actually going on is that you're now
enshrining as a "security" device a hacky, ill-conceived workaround
for a lack of flexibility/space/etc in IPv4.  NAT was not designed
to act as a security feature.

Hi Joe,

That would be one of those "details" on which smart people disagree.
In this case, I think you're wrong. Modern NAT superseded the
transparent proxies and bastion hosts of the '90s because it does the
same security job a little more smoothly. And proxies WERE designed to
act as a security feature.


You'd expect folks to give up two layers of security at exactly the
same time as they're absorbing a new network protocol with which
they're yet unskilled? Does that make sense to you from a
risk-management standpoint?

Actually, yes, it does.  Using the product as intended is substantially
less risky than trying to figure out how to use some sort of proxy or
gateway functionality to emulate NAT, and then screwing that up.

What sort of traction are you getting from that argument when you
speak with enterprise security folks?

Regards,
Bill Herrin



-- 
William D. Herrin ................ herrin () dirtside com  bill () herrin us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004


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