Re: Why /64

[Jeroen Massar <[e-mail]>]

On 2013-10-28 09:28, Wuyts Carl wrote:
> +1 for the /64 on the link and /48 for enterprise, 
> 
> but "at least" a /56 for home (with /60 too tiny) ??
> Can you elaborate on why you would need more than 4 bits subnets @ home?

Because I am one of the examples where I have, at home, already have
more than 16 VLANs at home.

But I might be special, I can only assume several other people here have
similar large home networks. I have so many VLANs as I like things in
separate networks, many do not even get Internet connectivity but they
are globally addressable. Note that things go very quickly when you have
things like IPv6 connected lightbulbs; though these are in a VLAN per
room so that I can send a multicast message to that VLAN and turn them
all on/off etc in one go.

The original point of the /48 was that nobody should have to bother
thinking about bits as there is enough space.

Clearly some ISPs see some scaling issues inside their network and thus
think that /56's solve that. Hence why ARIN at first then changed that
limit.

One routing slot though is still one routing slot, not more, thus if it
is a /56 or a /48 should not matter.

I am quite fine with a /56 for home users, it definitely works for me
and thus should for really everybody else in a home network.

But enterprises/companies should per default get a /48 per site so that
it is always the same and they can at least number-plan wise renumber
easily.

Hence the /64 link (autoconfig is great), /56 for enter home and /48 for
companies.

Greets,
 Jeroen


PS: one problem with the 'you get a /48' etc is that some ISPs steal the
first /64 for the uplink, some others do not. Hence why if one is doing
a network plan skip the first /64 as it will save some pain if you ever
switch. (Though it would just mean changing one VLAN to other bits).