RE: Why /64

[Wuyts Carl <[e-mail]>]

Ok, thx for the update.
I don't think that you're the "default/avg" user here :-), hence I don't believe they will use your setup as an example to set for a specific ia_pd prefix length.
I agree there's plenty of space, but lots of ISPs claim people said the same in IPv4 era, hence are cautious to set it "too big".

Anyway, I must say to see lots of /56s, so looks ok in lots of occasion, but for sure no global consensus / approach on this, I see anything between 64 and /48 for the home being used today.

Regs
Carl
-----Original Message-----
From: Jeroen Massar [mailto:[e-mail]] 
Sent: maandag 28 oktober 2013 9:46
To: Wuyts Carl; Octavio Alvarez
Cc: <[e-mail]>
Subject: Re: Why /64

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).