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


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