On Sat, 07 Feb 2009 14:31:57 -0500, Stephen Sprunk <step...@sprunk.org>
wrote:
Non-NAT firewalls do have some appeal, because they don't need to mangle
the packets, just passively observe them and open pinholes when
appropriate.
This is exactly the same with NAT and non-NAT -- making any anti-NAT
arguments null.
In the case of NAT, the "helper" has to understand the protocol to know
what traffic to map.
In the case of a stateful firewalling ("non-NAT"), the "helper" has to
understand the protocol to know what traffic to allow.
Subtle difference, but in the end, the same thing... if your gateway
doesn't know what you are doing, odds are it will interfere with it. In
all cases, end-to-end transparency doesn't exist. (as has been the case
for well over a decade.)
--Ricky