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Re: mh (RE: OMB: IPv6 by June 2008)

  • From: Crist Clark
  • Date: Fri Jul 08 17:14:49 2005 
Jay R. Ashworth wrote:

On Fri, Jul 08, 2005 at 01:15:42PM -0400, David Andersen wrote:


On Jul 8, 2005, at 12:49 PM, Jay R. Ashworth wrote:


On Thu, Jul 07, 2005 at 01:31:57PM -0700, Crist Clark wrote:


And if you still want "the protection of NAT," any stateful firewall
will do it.

That seems a common viewpoint.

I believe the very existence of the Ping Of Death rebuts it.

A machine behind a NAT box simply is not visible to the outside world,
except for the protocols you tunnel to it, if any.   This *has* to
vastly reduce it's attack exposure.

Not really.  Consider the logic in a NAT box:

[ ... ]


and the logic in a stateful firewall:

Sorry.  Given my other-end-of-the-telescope perspective, I was
envisioning an *on-machine* firewall, rather than a box.  Clearly *any*
sort of box in the middle helps in the fashion I alluded to, whether it
NATs or not.

Now I'm confused. Who runs *on-machine* NAT?

I guess that's another nice option for firewalls. It doesn't matter
whether your firewall runs locally or on a remote gateway.

Also, when people here are talking about NAT, note that we are only
talking about many-to-one, overloading, PAT, or whatever you want
to call it. If you are using NAT pools or one-to-one NAT, it buys
you no protection at all unless you add firewalling to the mix.
--
Crist J. Clark                               [email protected]
Globalstar Communications                                (408) 933-4387