Re: Dual stack IPv6 for IPv4 depletion

[Josh Moore <jmoore () atcnetworks net>]

Performing the NAT on the border routers is not a problem. The problem comes into play where the connectivity is not 
symmetric. Multiple entry/exit points to the Internet and some are load balanced. We'd like to keep that architecture 
too as it allows for very good protection in an internet link failure 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:
>
> WISPs have been good at solving this, as they are often deploying greenfield networks. They use private IPv4 
> internally and NAT IPv4 at multiple exit points. IPv6 is seamlessly redundant, since customers all receive global 
> /64s; BGP handles failover. If you home multiple upstream providers on a single NAT gateway hardware stack, 
> redundancy is also seamless, since your NAT tables are synced across redundant stack members.  If you have separate 
> stacks, 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 the gateways. Most WISPs don't.  
>
> -mel beckman
>
> > On Jul 5, 2015, at 7:25 AM, Josh Moore <jmoore () atcnetworks net> wrote:
> >
> > So the question is: where do you perform the NAT and how can it be redundant?
> >
> >
> >
> >
> > Thanks,
> >
> > Joshua Moore
> > Network Engineer
> > ATC Broadband
> > 912.632.3161
> >
> > > On Jul 5, 2015, at 10:12 AM, Mel Beckman <mel () beckman org> wrote:
> > >
> > > Josh,
> > >
> > > Your job is simple, then. Deliver dual-stack to your customers and if they want IPv6 they need only get an 
> > > IPv6-enabled firewall. Unless you're also an IT consultant to your customers, your job is done. If you already 
> > > supply the CPE firewall, then you need only turn on IPv6 for customers who request it. With the right kind of CPE, 
> > > you can run MPLS or EoIP and deliver public IPv4 /32s to customers willing to pay for them. Otherwise it's private 
> > > IPv4 and NAT as usual for IPv4 traffic. 
> > >
> > > -mel via cell
> > >
> > > > On Jul 5, 2015, at 6:57 AM, Josh Moore <jmoore () atcnetworks net> wrote:
> > > >
> > > > We are the ISP and I have a /32 :)
> > > >
> > > > I'm simply looking at the best strategy for migrating my subscribers off 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.
> > > >
> > > >
> > > >
> > > >
> > > > Thanks,
> > > >
> > > > Joshua Moore
> > > > Network Engineer
> > > > ATC Broadband
> > > > 912.632.3161
> > > >
> > > > On Jul 5, 2015, at 9:55 AM, Mel Beckman <mel () beckman org> wrote:
> > > >
> > > > > > Josh Moore wrote:
> > > > > >
> > > > > > 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.
> > > > >
> > > > > No, tunnels do give you one to one global IPv6 address mapping for every device. From a testing perspective, a 
> > > > > tunnelbroker  works just as if you had a second IPv6-only ISP. If you're fortunate enough to have a dual-stack 
> > > > > ISP already, you can forgo tunneling altogether and just use an IPv6-capable border firewall. 
> > > > >
> > > > > 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* do
> > > > > > IPv6 with tunnels and cannot do IPv6 on PPPoE. Go figure. So there is
> > > > > > not exactly a clear path to native IPv6 for your lab this way.
> > > > >
> > > > > Nobody is recommending the Apple router as a border firewall. It's terrible for that. But it's a ready-to-go 
> > > > > tunnelbroker gateway. If your ISP can't deliver IPv6, tunneling is the clear path to building a lab. If you have 
> > > > > a dual-stack ISP already, the clear path is to use an IPv6-capable border firewall. 
> > > > >
> > > > > So you are in a maze of non-twisty paths, all alike :)