Re: [v6ops] I-D Action: draft-colitti-v6ops-host-addr-availability-01.txt

[Andrew 👽 Yourtchenko <[e-mail]>]

On 7/28/15, Gert Doering <[e-mail]> wrote:
> Hi,
>
> On Mon, Jul 27, 2015 at 03:25:18PM +0200, Andrew ????  Yourtchenko wrote:
>> The disjoint nature of IA_NA means a corresponding number of TCAM
>> entries is required on L3 switches.
>>
>> A prefix, on the other hand, requires just an entry for the link-local
>> of the host + an entry for the prefix. Regardless of the prefix
>> length.
>
> All true.  But then you excercise pressure on the prefix allocation side
> - instead of having "one /64 for that LAN segment, which is big enough
> for arbitrary number of hosts" you end up with "a /52[-ish] per LAN segment
> to cover DHCP-PD delegation to thousands of hosts".
>
> (Say, 1000 hosts, all doing DHCP-PD and requesting a single /64, you'd
> need to provision at least a /54 per segment - which will increase your
> prefix usage enormously)
>
> Is that what you want?

I did not look at it as a problem given that every mobile phone on
IPv6 will already get a /64 per host, and the number of mobile phones
is dramatically bigger than the number of fixed installations.

But I pulled that assumption more or less out of my thumb, based on
observed anecdata, so would be happy to be proven wrong.

If we say we want to absolutely avoid NAT, then something has to give,
and I don't know which tradeoff is a better one, both can be argued
for and against. I think we might need both.

--a


>
> Gert Doering
>         -- NetMaster
> --
> have you enabled IPv6 on something today...?
>
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