Re: Extending a /64

[Philip Homburg <[e-mail]>]

> Well that's the big bit of the jigsaw puzzle you've probabl
>y overlooked - those "big aircraft" are but a tiny proportion of the world's air
>craft. There are orders of magnitude more aircraft where if it doesn't fit in th
>e panel in front of the pilot, then it isn't getting fitted. And probably a simi
>lar number that have no electrical system, or only a small battery powered syste
>m - the norm with gliders where there's probably just a single radio and a vario
>, all run off a small battery.
>And it's not unusual to be operating these smaller aircraft outside of radio cov
>erage - so no communications with the ground - and from sites with no infrastruc
>ture (such as grass field with a shed at one side). And don't forget that balloo
>ns are also aircraft - no electrical system in the wicker basket !

We talking about a table that has 500k entries. It is hard to imagine how
tiny the silicon is that is needed to store such a table. Same thing for
power requirements. By the time you have a device that can talk IPv6 over
radio, you have the space and energy budget to store such a table.

However, this seems to be a case of doing things at the wrong level. If aircaft
use IPv6 to communicate then obvious they need unique IPv6 addresses. However,
each plane only needs to know its own address. Any time a plane communicates
with an unknown plane, they can exchange higher level identities.

So, before take off, a pilot can install an up-to-date list of all aircraft. Even
if you would use technology of 20 years ago, that would take only a tiny amount
of space.

However, in any sensible protocol, aircaft would only need to know the mapping
for their own registration number at take off and then learn about other planes
during the flight. So the table would be installed/updated when the aircrafts
identity is installed/updated.

I don't understand your remark about balloons. If balloons have no electrical
systems, how do they run IPv6? 

In any case, if you would need a complete table, then that would get updated
before take off. For example, you put an up-to-date table on a phone, connect
the phone to the communications module in the plane and transfer the table.