Re: [OPSAWG] [v6ops] Heads up - Plea for allocating a /8 to ISPs
Brian E Carpenter <[email protected]>
| Newsgroups | gmane.ietf.ops,gmane.ietf.v6ops |
|---|---|
| Organization | University of Auckland |
| Message-ID | <[email protected]> |
Chris,
On 2010-11-12 19:43, Christopher LILJENSTOLPE wrote:
> It's not being used for internal devices, please re-read the draft. It is to enable NAT444 to allow the delivery of IPv4 services, after run-out, using NAT444, to act as the v4 substrate between a CPE supporting 1918 to the customer, and the public internet.
Isn't it more precisely:
"the v4 substrate between a CPE/NAT supporting 1918 to the customer, and a CGN that
connects to the public internet."
Do you have a canonical value for the maximum number of customers
that can be served by one CGN? That sets a bound on the length of prefix
you need (assuming Balkanized routing within the ISP, which I presume
is going to be SOP).
For example 100,000 customers would need a /15, re-used for each CGN.
A /10 appears to be enough for 2*22 customers per CGN, which seems
like more than plenty.
Even a /12 seems generous: 1M customers per CGN.
So my bottom line is: use 172.16/12; and a minority of customers
will have to renumber internally into 10/8.
That is IMHO much better than breaking everything that has RFC 1918
knowledge built into it.
Brian