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

[Justin Streiner <streinerj () gmail com>]

We went pretty deep into the weeds on NAT in this thread - far deeper than
I expected ;)

Getting back to the recently revised topic of this thread - IPv6 uptake -
what have peoples' experiences been related to crafting sane v6 firewall
rulesets in recent products from the major firewall players (Palo Alto,
Cisco, Fortinet, etc)?  On the last major v6 deployment I did, working with
the firewalls was definitely one of the major pain points because the
support / stability was really lacking, or there wasn't full feature parity
between their v4 and v6 capabilities.

Thank you
jms

On Fri, Feb 16, 2024 at 11:04 PM William Herrin <bill () herrin us> wrote:

> On Fri, Feb 16, 2024 at 7:41 PM John R. Levine <johnl () iecc com> wrote:
> > > That it's possible to implement network security well without using
> > > NAT does not contradict the claim that NAT enhances network security.
> >
> > I think we're each overgeneralizing from our individual expeience.
> >
> > You can configure a V6 firewall to be default closed as easily as you can
> > configure a NAT.
>
> Hi John,
>
> We're probably not speaking the same language. You're talking about
> configuring the function of one layer in a security stack. I'm talking
> about adding or removing a layer in a security stack. Address
> overloaded NAT in conjunction with private internal addresses is an
> additional layer in a security stack. It has security-relevant
> properties that the other layers don't duplicate. Regardless of how
> you configure it.
>
> Also, you can't "configure" a layer to be default closed. That's a
> property of the security layer. It either is or it is not.
>
> You can configure a layer to be "default deny," which I assume is what
> you meant. The issue is that anything that can be configured can be
> accidentally unconfigured. When default-deny is accidentally
> unconfigured, the network becomes wide open. When NAT is accidentally
> unconfigured, the network stops functioning entirely. The gate is
> closed.
>
> Regards,
> Bill Herrin
>
>
> --
> William Herrin
> bill () herrin us
> https://bill.herrin.us/