Re: I-D Action: draft-mishra-6man-variable-slaac-01.txt

[Brian E Carpenter <[e-mail]>]

Hi authors,

> 8.  Greater than 64 bit prefix usage by ISPs is strictly prohibited
> 
>    The RA flag S bit setting proposed by this draft for greater or less
>    then /64 bit prefix feature is strictly for enterprises and broadband
>    subscriber customer use only. 

How do you propose to enforce this, to prevent a race to the bottom
between ISPs? Do you have a funding source for the new Protocol Police?

It's hard to see why this draft is needed anyway. All that is needed
is to remove the "64 bit" statement from the addressing architecture,
which the WG has consistently failed to reach consensus about.

>    o  1: Variable length interface identifier is enabled (ignored by
>       hosts not supporting)

How does this work if the router expects hosts to use shorter IIDs but
hosts in fact use standard 64 bit IIDs? As far as I can see, SLAAC,
DAD and default address selection will only work correctly if all
nodes on a given link agree about the prefix and IID lengths. For
all existing devices, the baked-in code assumes that both are 64.

If a 64 bit node wants to send to a destination with the same
64 bit prefix that is in fact off-link because the on-link prefix
is actually supposed to be /68, what happens?

Regards
   Brian