Rate of growth on IPv6 not fast enough?

Owen DeLong owen at delong.com
Mon Apr 19 16:01:03 CDT 2010

On Apr 19, 2010, at 1:52 PM, William Herrin wrote:

> On Mon, Apr 19, 2010 at 1:22 PM, Bryan Fields <Bryan at bryanfields.net> wrote:
>> On 4/19/2010 10:14, Patrick Giagnocavo wrote:
>>> The eyeball ISPs will find it trivial to NAT should they ever need to do
>>> so however, something servers cannot do - you are looking at numbers,
>>> not operational considerations.
>> LSN is not trivial.
>> Here is some unverified calculations I did on the problem of scaling nat.
>> Right now I'm using 42 translation entries in my nat table.  Each entry takes
>> up 312 bytes of FIB memory, which is ~12.7 Kib of data in the FIB.  Mutiply
>> this by 250k users and we have 3,124,237 KiB of FIB entries, or 3.1 GiB.  This
>> is not running any PtP programs or really hitting the network, I'm just
>> browsing the web and typing this email to you.
> Bryan,
> Is there some reason we believe we need to scale individual NAT
> systems beyond about 1000 users each in order to have the desired
> impact on address recapture/reuse? Growing towards 7B people in the
> world with, let's say, 4 connected client devices each, grouped 1000
> per NAT box requires 7B * 4 / 1K = 28M or 1.7 /8's for the eyeball
> networks before structural overhead.
> Pushing a carrier NAT process shallow has its own set of complications
> (and certainly isn't trivial) but raw scalability doesn't look like
> one of the problems.

The hardware cost of supporting LSN is trivial. The management/maintenance
costs and the customer experience -> dissatisfaction -> support calls -> employee
costs will not be so trivial. 

These facts make me very glad that my networks will NOT be implementing
LSN in any form.


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