[181808] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Josh Moore)
Sun Jul 5 11:11:24 2015
X-Original-To: nanog@nanog.org
From: Josh Moore <jmoore@atcnetworks.net>
To: Mel Beckman <mel@beckman.org>
Date: Sun, 5 Jul 2015 15:11:12 +0000
In-Reply-To: <FA5CB3F5-C6FE-469F-8910-5A3FA4032694@beckman.org>
Cc: "johnl@iecc.com" <johnl@iecc.com>, "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
Performing the NAT on the border routers is not a problem. The problem come=
s into play where the connectivity is not symmetric. Multiple entry/exit po=
ints to the Internet and some are load balanced. We'd like to keep that arc=
hitecture too as it allows for very good protection in an internet link fai=
lure scenario and provides BGP best path connectivity.
So traffic cones in ISP A might leave ISP B or traffic coming in ISP A may =
come in ISP B simultaneously.
Thanks,
Joshua Moore
Network Engineer
ATC Broadband
912.632.3161
> On Jul 5, 2015, at 10:43 AM, Mel Beckman <mel@beckman.org> wrote:
>=20
> WISPs have been good at solving this, as they are often deploying greenfi=
eld networks. They use private IPv4 internally and NAT IPv4 at multiple exi=
t points. IPv6 is seamlessly redundant, since customers all receive global =
/64s; BGP handles failover. If you home multiple upstream providers on a si=
ngle NAT gateway hardware stack, redundancy is also seamless, since your NA=
T tables are synced across redundant stack members. If you have separate s=
tacks, or even sites, IPv4 can fail over to an alternate NAT Border gateway=
but will lose session contexts, unless you go to the trouble of syncing th=
e gateways. Most WISPs don't. =20
>=20
> -mel beckman
>=20
>> On Jul 5, 2015, at 7:25 AM, Josh Moore <jmoore@atcnetworks.net> wrote:
>>=20
>> So the question is: where do you perform the NAT and how can it be redun=
dant?
>>=20
>>=20
>>=20
>>=20
>> Thanks,
>>=20
>> Joshua Moore
>> Network Engineer
>> ATC Broadband
>> 912.632.3161
>>=20
>>> On Jul 5, 2015, at 10:12 AM, Mel Beckman <mel@beckman.org> wrote:
>>>=20
>>> Josh,
>>>=20
>>> Your job is simple, then. Deliver dual-stack to your customers and if t=
hey want IPv6 they need only get an IPv6-enabled firewall. Unless you're al=
so an IT consultant to your customers, your job is done. If you already sup=
ply the CPE firewall, then you need only turn on IPv6 for customers who req=
uest it. With the right kind of CPE, you can run MPLS or EoIP and deliver p=
ublic IPv4 /32s to customers willing to pay for them. Otherwise it's privat=
e IPv4 and NAT as usual for IPv4 traffic.=20
>>>=20
>>> -mel via cell
>>>=20
>>>> On Jul 5, 2015, at 6:57 AM, Josh Moore <jmoore@atcnetworks.net> wrote:
>>>>=20
>>>> We are the ISP and I have a /32 :)
>>>>=20
>>>> I'm simply looking at the best strategy for migrating my subscribers o=
ff v4 from the perspective of solving the address utilization crisis while =
still providing compatibility for those one-off sites and services that are=
still on v4.
>>>>=20
>>>>=20
>>>>=20
>>>>=20
>>>> Thanks,
>>>>=20
>>>> Joshua Moore
>>>> Network Engineer
>>>> ATC Broadband
>>>> 912.632.3161
>>>>=20
>>>> On Jul 5, 2015, at 9:55 AM, Mel Beckman <mel@beckman.org> wrote:
>>>>=20
>>>>>>=20
>>>>>> Josh Moore wrote:
>>>>>>=20
>>>>>> Tunnels behind a CPE and 4to6 NAT seem like bandaid fixes as they do=
not give the benefit of true end to end IPv6 connectivity in the sense of =
every device has a one to one global address mapping.
>>>>>=20
>>>>> No, tunnels do give you one to one global IPv6 address mapping for ev=
ery device. From a testing perspective, a tunnelbroker works just as if yo=
u had a second IPv6-only ISP. If you're fortunate enough to have a dual-sta=
ck ISP already, you can forgo tunneling altogether and just use an IPv6-cap=
able border firewall.=20
>>>>>=20
>>>>> William Waites wrote:
>>>>>> I was helping my
>>>>>> friend who likes Apple things connect to the local community
>>>>>> network. He wanted to use an Airport as his home gateway rather than
>>>>>> the router that we normally use. Turns out these things can *only* d=
o
>>>>>> IPv6 with tunnels and cannot do IPv6 on PPPoE. Go figure. So there i=
s
>>>>>> not exactly a clear path to native IPv6 for your lab this way.
>>>>>=20
>>>>> Nobody is recommending the Apple router as a border firewall. It's te=
rrible for that. But it's a ready-to-go tunnelbroker gateway. If your ISP c=
an't deliver IPv6, tunneling is the clear path to building a lab. If you ha=
ve a dual-stack ISP already, the clear path is to use an IPv6-capable borde=
r firewall.=20
>>>>>=20
>>>>> So you are in a maze of non-twisty paths, all alike :)
