Re: Addressing plan exercise for our IPv6 course

[Marco Hogewoning <marcoh () marcoh net>]

On 21 jul 2010, at 19:22, Simon Perreault wrote:

> On 2010-07-21 12:57, Alex Band wrote:
> > We've been working on an exercise for the IPv6 training course we deliver for LIRs. It's aimed at people who are 
> > unfamiliar with IPv6, so the goal is to get them to the point where once they get their IPv6 /32 allocation, they 
> > have a good idea how to subdivide prefixes over their network and how to write an addressing plan.
> >
> > Here's a PDF with the exercise (two pages A3): http://bit.ly/c7jZRJ
> >
> > I'm curious to hear if you think it's clear and useful.
>
> Useful, yes. But it should be clearer that not all address plans are
> equally good. It's not just a matter of filling in the blanks with
> something that will work.

Every address plan will turn out to be a custom job anyway. Primary goal of this exercise is to show the basics and to 
show how you can get a lot of aggregation done without wasting a lot of space. Making people familiar with the way 
subnets are split up and the very basics of counting to 16.

I'm also working on a more extensive half day workshop which contains a lot more scenarios and for instance show how to 
fit this same network into a /48 PI assignment instead of the /32 PA. If you are bored with this one already, go ahead 
and try :)

> For instance, would one be expected to follow RFC 3531?

For a novice ? I wouldn't recommend it. From what I get back 'in the field' it's already hard enough to get people 
familliar to the whole concept of hexadecimal without going into bit level. But then again, if you are a fairly 
technical company maybe you can get away with it.

As far as customer assignments is concerned, I would simply stick to the /48 and not make any reservation for future 
growth beyond that, i should probably cater for 99% of your cases and if they really run out I can probably handle a 
second assignment/route for another one (or leave them the choice to renumber into a /47). In fact part of this 
exercise is meant to teach people how to avoid such disasters as running 'out of space' by being really inefficient.

The only way where I see this becoming relevant is when trying to make subassignments from a /48. But as far as PI is 
concerned, and that would be the most likely case, in RIPE region you are not allowed to make subassignments from 
within a PI block. The other one would be subassignments from a PA block, which under the same policy can easily be 
made a few bits bigger and if I would encounter a customer who would actually subassign large numbers of customers from 
within a PA assignment. I would recommend becoming an LIR themselves and get a /32.

MarcoH