IPv6 uptake (was: The Reg does 240/4)

Sat Feb 17 18:29:59 UTC 2024

Most firewalls are default deny. Routers are default allow unless you put a filter on the interface.

NAT adds nothing to security (Bill and I agree to disagree on this), but at best, it complicates the audit trail. 

Owen

> On Feb 16, 2024, at 15:19, Jay R. Ashworth <jra at baylink.com> wrote:
> 
> ----- Original Message -----
>> From: "William Herrin" <bill at herrin.us>
> 
>> On Fri, Feb 16, 2024 at 2:19 PM Jay R. Ashworth <jra at baylink.com> wrote:
>>>> From: "Justin Streiner" <streinerj at gmail.com>
>>>> 4. Getting people to unlearn the "NAT=Security" mindset that we were forced
>>>> to accept in the v4 world.
>>> 
>>> NAT doesn't "equal" security.
>>> 
>>> But it is certainly a *component* of security, placing control of what internal
>>> nodes are accessible from the outside in the hands of the people inside.
>> 
>> Every firewall does that. What NAT does above and beyond is place
>> control of what internal nodes are -addressable- from the outside in
>> the hands of the people inside -- so that most of the common mistakes
>> with firewall configuration don't cause the internal hosts to -become-
>> accessible.
>> 
>> The distinction doesn't seem that subtle to me, but a lot of folks
>> making statements about network security on this list don't appear to
>> grasp it.
> 
> You bet.  I knew someone would chime in, but whether they'd be agreeing
> with me -- as you are -- or yelling at me, wasn't clear.
> 
> It's a default deny (NAT) vs default allow (firewall) question, and
> I prefer default deny -- at least inbound.  You *can* run NAT as default
> deny outbound, too, but it's much less tolerable for general internet
> connectivity -- in some dedicated circumstances, it can be workable.
> 
> Cheers,
> -- jra
> --
> Jay R. Ashworth                  Baylink                       jra at baylink.com
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