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Date:      Tue, 29 Jul 2014 01:21:53 +0200
From:      Mark Martinec <Mark.Martinec+freebsd@ijs.si>
To:        freebsd-current@freebsd.org
Cc:        Kevin Oberman <rkoberman@gmail.com>
Subject:   Re: Future of pf / firewall in FreeBSD =?UTF-8?Q?=3F=20-=20does?= =?UTF-8?Q?=20it=20have=20one=20=3F?=
Message-ID:  <331930d6178ebbed522e9eddff0196fc@mailbox.ijs.si>
In-Reply-To: <CAN6yY1uHJn4xA-5zFr4fZez3FyXi7tT0LmhyR8yWkqG7k1A%2B=A@mail.gmail.com>
References:  <201407261843.s6QIhcx4008597@slippy.cwsent.com> <53D61AC6.5030305@freebsd.org> <CAN6yY1uHJn4xA-5zFr4fZez3FyXi7tT0LmhyR8yWkqG7k1A%2B=A@mail.gmail.com>

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> On Mon, Jul 28, 2014 at 2:41 AM, Darren Reed <darrenr@freebsd.org>=20
> wrote:
>> [...]
>> IPFilter 5 does IPv6 NAT.
>>=20
>> With the import of 5.1.2, map, rdr and rewrite rules will all work=20
>> with
>> IPv6 addresses.
>>=20
>> NAT66 is a specific implementation of IPv6 NAT behaviour.

2014-07-29 00:07 Kevin Oberman wrote:
> And all IPv6 NAT is evil and should be cast into (demonic residence of=20
> your
> choosing) on sight!
>=20
> NAT on IPv6 serves no useful purpose at all. It only serves to=20
> complicate
> things and make clueless security officers happy. It adds zero=20
> security. It
> is a great example of people who assume that NAT is a security feature=20
> in
> IPv4 (it's not) so it should also be in IPv6.
>=20
> The problem is that this meme is so pervasive that even when people
> understand that it is bad, they still insist on it because there will=20
> be an
> unchecked box on the security checklist for "All systems not pubic=20
> servers
> are in RFC1918 space? -- YES   NO". The checklist item should be=20
> (usually)
> "All systems behind a stateful firewall with an appropriate rule set?=20
> --
> YES  NO" as it is a stateful firewall (which is mandatory for NAT that
> provides all of the security.
>=20
> I say "usually" because the major research lab where I worked ran=20
> without a
> firewall (and probably still does) and little, if any, NAT. It was=20
> tested
> regularly by red teams hired by the feds and they never were able to
> penetrate anything due to a very aggressive IDS/IPS system, but most=20
> people
> and companies should NOT go this route. I have IPv6 at home (Comcast)=20
> and
> my router runs a stateful firewall with a rule set functionally the=20
> same as
> that used for IPv4 and that provides the protection needed.
>=20
> So putting support for NAT66 or any IPv6 NAT into a firewall is just=20
> making
> things worse. Please don't do it!
> --
> R. Kevin Oberman, Network Engineer, Retired
> E-mail: rkoberman@gmail.com

You are missing the point, we are talking about NAT64 (IPv6-only=20
datacenter's
path to a legacy world), and NPT66 (prefix transalation). I doubt anyone=20
had
a traditional NAT in mind.

Consider a small site with uplinks to two service providers: it can use=20
ULA
internally and translate prefix on each uplink.

Please see these short blogs:

- To ULA or not to ULA, That=E2=80=99s the Question
  =20
http://blog.ipspace.net/2013/09/to-ula-or-not-to-ula-thats-question.html

- I Say ULA, You Hear NAT
   http://blog.ipspace.net/2014/01/i-say-ula-you-hear-nat.html

- PA, PI or ULA IPv6 Address Space? It depends
  =20
http://blog.ipspace.net/2014/01/pa-pi-or-ula-ipv6-address-space-it.html

- Source IPv6 Address Selection Saves the Day
  =20
http://blog.ipspace.net/2014/01/source-ipv6-address-selection-saves-day.htm=
l


Mark



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