Persistent or opportunistic IDs

[Iljitsch van Beijnum <iljitsch@muada.com>]

Yesterday at the RIPE meeting Geoff talked about the difference between 
doing address agility using long-lived identifiers vs pragmatic, 
short-lived identifiers. This is indeed a useful way to classify multi6 
solutions. Pragmatic identifiers would generally be regular (locator) 
IP address. However, selecting such a pragmatic approach doesn't 
necessarily close the door on persistent identifiers, as it's possible 
to "hide" such a persistent identifier in the lower 64 bits of a PA 
IPv6 address. This is basically what I propose in my crypto-based host 
identifier draft.

Two questions:

- do we agree that going the pragmatic route first and adding 
persistent identifiers later is indeed possible?
- if this is the case, does this mean such is also the preferable way 
forward?