multiple prefixes

[Doug Barton]

On 02/12/2013 12:22 AM, Lorenzo Colitti wrote:
> On Tue, Feb 12, 2013 at 5:18 PM, Doug Barton <dougb at dougbarton.us
> <mailto:dougb at dougbarton.us>> wrote:
>
>
> Higher operational cost caused by more complex, stateful operation
> of the network. Lower reliability due to NAT leading to loss of said
> state and interrupted sessions. Higher capex caused by boxes having
> to do more complex stuff (NAT vs. route). Higher cost and a higher
> barrier to entry for application developers as they each have to
> re-learn NAT traversal (and no, NAT traversal is *not* the same as
> traversing a stateful firewall - that's easier). Lower quality of
> service when said applications perform worse. Believe it or not,
> Skype on my phone works better on the a one-NAT 3G network than on a
> double-natted 1Gbps fiber connection.
>
>
> What you described were all costs of NAT, no argument.
>
> Now can you please describe how those things are relevant to NPTv6?
>
>
> Take out the costs that are due to stateful inspection (and remember,
>  translation is more expensive than forwarding) and leave the rest.

I'm pretty sure you're wrong about almost all of what you wrote above in 
regards to NPT, and that you're applying an anti-NAT prejudice because 
it looks similar.

 > Higher capex caused by boxes having to do more complex stuff (NAT vs. 
route).

NPT isn't NAT. It's very likely that any extra costs for gear that can 
do NPT are going to be in the noise, but I do admit that this is 
something that remains to be seen.

 > Higher cost and a higher
 > barrier to entry for application developers as they each have to
 > re-learn NAT traversal (and no, NAT traversal is *not* the same as
 > traversing a stateful firewall - that's easier).

Please demonstrate how these costs pertain to NPT. To the application 
there shouldn't be any difference between operating in an NPT 
environment than operating on GUAs. (This response also applies to your 
comment about skype.)

Doug