RE: IPv6 prefixes longer then /64: are they possible in DOCSIS networks?

[Nathan Eisenberg <nathan () atlasnetworks us>]

> To be honest, I can't work out the point of preferring a /64 in the
> first place if
> you're not using SLAAC and I'm not sure why SLAAC wanted more than 48
> bits.
>
> If you use broad ACLs to lock down to a /126 or /112 equivalent, why
> bother with
> the /64 in the first place?
>
> However, I'm new to the IPv6 business, so I'm sure I'll work it out
> eventually.

Or you might do what a lot of us have done: get sick of arguing with the evangelists about how /64's don't make sense 
for everyone in every scenario.  Get sick of trying to argue that every home's CPE doesn't need a /48 delegated to it 
so that it can automatically subdelegate longer networks to devices which will in turn subdelegate even longer prefixes 
to devices which "something that hasn't been invented yet will use, and if you don't set it up this way, history will 
prove that you're an unimaginative fool".  Get sick of hearing "It's a huge address space, so don't worry about being 
conservative - sitting 'on the shelf' or sitting unused in a network are the same thing" (I guess we'll migrate to an 
even bigger address space if we someday have other stellar bodies in our local star system to send packets to, despite 
the average home network utilizing far, far less than .00[...]01% of their address space... - add a lot more 0's if the 
/48 guys win out...)

This new IPv6 world is full of lazy evangelists, who are so excited about same-sized subnets, stateless address 
configuration and globally unique and routable addresses for purposes that no one can quite imagine yet, that they 
cannot engage in a logical and rational discussion with the rest of us.  Instead, we go back and forth over the same 
concerns, until the patience of the list has been utterly worn out - at which point, these individuals always throw 
their hands in the air, and exclaim: "You're wrong, and your customers will tell you that with their feet", and presume 
that they have then proven you wrong.

As has been pointed out, there is a lot of human nature at work here: these individuals have made low-level emotional 
investments in their arguments, and divided the IPv6-think world into two categories: Us (right), and Not Us (wrong).  
When someone does this, it can take a significant amount of psychology to get the conversation to a rational place, and 
unless you have a real need to see eye to eye with them, it's often easier to move on.  In any case, do the research 
and testing, and make sure that at least your own deployments have rational addressing policies (whatever you determine 
that might be).

Nathan Eisenberg