Is NAT can provide some kind of protection?

Mark Smith nanog at
Sat Jan 15 21:47:47 CST 2011

On Sat, 15 Jan 2011 18:39:09 -0500 (EST)
Brandon Ross <bross at> wrote:

> On Sun, 16 Jan 2011, Mark Smith wrote:
> > How do you know - have you asked 100% of the service providers out
> > there and they've said unanimously that they're only going to supply a
> > single IPv6 address?
> Huh?  Who said anything about 100%? 

I think you did ..

"Service providers will continue to assign only a single IP address to 
residential users unless they pay an additional fee for additional 

 It would take only a single 
> reasonably sized provider that has a monopoly in a particular area (tell 
> me that doesn't happen) or a pair of them that have a duopoly (almost 
> everywhere in the US) and you instantly have huge incentive for someone to 
> write some v6 PAT code.

And that will create a "huge incentive" for people to acquire larger
amounts of address space via other mechanisms, such as 6to4, tunnels,
changing to another provider etc.

> Believe me, I'm the last person who wants to see this happen.  It's a 
> horrible, moronic, bone-headed situation.  Unfortunately, I'm pretty sure 
> it's going to happen because it's been the status quo for so long, and 
> because some marketing dweeb will make the case that the provider is 
> leaving revenue on the table because there will always be some customers 
> who aren't clever enough to use NAT and will buy the upgraded "5 pack" 
> service.

I'm confident the opposite will happen. People on this list and similar
ones usually understand the value of more than one public
address for a home, and commonly enough have routed subnets to their
homes, courtesy of their employer, and have probably also been burnt by
NAT. They'll be the ones who tell their management "this is how IPv6 is
deployed". If they're ignored, they should then say, "and this is how
our competitors will be deploying IPv6".

Even though customers may not completely understand what they're
getting, if one provider has a marketing bullet point of "1 IPv6
address", and another has a marketing bullet point of "Millions of IPv6
addresses", people will just assume more is better and go with the

There is no point pretending IPv6 addresses are expensive or trying to
make them artificially so.

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