Minimum IPv6 size

Brandon Butterworth brandon at
Sun Oct 4 15:16:59 UTC 2009

> > If there are to be filters then they should be defined once and never
> > changed as people will fail to update
> Yay!  We can return to classful routing again.  That sure worked out well
> for us the first time around.  ^_^;

We have already, all we're discussing now is if we do a better job
of implementing it.

Classful suffered from lack of space in each range and too coarse a
set of fixed ranges, all fixable in v6 so perhaps it's not so bad?

> So, if I need to break up my /32 into 4 /34s to cover different geographical
> regions, I should instead renumber into a new range set aside for /34s
> and give back the /32?

And what if you need a few /48's, then you're open to others
advertising some of yours too.

With no organised mechanism of communicating acceptable prefix lengths
to all routers [1] then we either do nothing and let anarchy rule, do
something that overly constrains or do half the job and have both

> Perhaps we should give everyone an allocation out of each filter
> range, so that they can simply number from the appropriately-classed
> range; when you apply for space, you'd get a /32, a /33, a /34, a /35,
> a /36, etc. all from the appropriate, statically defined ranges.
> *removes tongue from cheek*

What would be most efficient for all? Semi classful or not I don't mind
but it does seem pointless to have been going round the same circle for
so many years.


[1] sbgp would be secure anarchy

More information about the NANOG mailing list