It's Ars Tech's turn to bang the IPv4 exhaustion drum

Tue Aug 19 18:05:37 UTC 2008

On Tue, 19 Aug 2008, Michael Thomas wrote:
> Justin M. Streiner wrote:
> >
> > I don't operate an ISP network (not anymore, anyway...).  My customers
> > are departments within my organization, so a /64 per department/VLAN
> > is more sane/reasonable for my environment.
>
> Uh, the lower 64 bits of an IP6 address aren't used for routing you
> know? They're essentially the mac address, or some other sort of
> autoconf'd host identifier. Last I heard, the smallest allocation is
> supposed to be a /48 -- I hadn't heard of the /56 thing that Michael was
> speaking of, though I'm not surprised. There's 64 bits for routing... no
> need to be so stingy :)

It doesn't make sense to allocate a /48 to a (V)LAN. Address
autoconfiguration is based on the assumption that the only
reason for having more than one global /64 prefix on a LAN
is during renumbering.

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/
HEBRIDES BAILEY FAIR ISLE FAEROES: NORTH OR NORTHEAST 5 OR 6 DECREASING 4 OR
5, BECOMING VARIABLE 3 IN NORTH BAILEY AND WEST FAEROES LATER. MODERATE OR
ROUGH. MAINLY FAIR. MODERATE OR GOOD.