IPv6 woes - RFC

Thu Sep 23 21:11:24 UTC 2021

So a single level of NAT and a similar level of customers to that which was
stated could be supported by a single IP.  This is not quite a apples to
apples comparison to the double NAT scenario being described below but
close enough for the number of sessions.

Mark

> On 24 Sep 2021, at 01:34, Colton Conor <colton.conor at gmail.com> wrote:
> 
> 300 apartments Mark. No, it's bulk internet and wifi so a single provider.
> 
> On Wed, Sep 22, 2021 at 8:01 PM Mark Andrews <marka at isc.org> wrote:
>> 
>> And how many apartments where covered by that single IP address? Was this
>> where there is a restriction on other providers so the occupants had no
>> choice of wireline ISP?
>> 
>>> On 23 Sep 2021, at 09:38, Colton Conor <colton.conor at gmail.com> wrote:
>>> 
>>> Where does this "You can only have about 200-300 subscribers per IPv4
>>> address on a CGN." limit come from? I have seen several apartment
>>> complexes run on a single static IPv4 address using a Mikrotik with
>>> NAT.
>>> 
>>> On Wed, Sep 22, 2021 at 2:49 PM Baldur Norddahl
>>> <baldur.norddahl at gmail.com> wrote:
>>>> 
>>>> 
>>>> 
>>>> On Wed, 22 Sept 2021 at 16:48, Masataka Ohta <mohta at necom830.hpcl.titech.ac.jp> wrote:
>>>>> 
>>>>> Today, as /24 can afford hundreds of thousands of subscribers
>>>>> by NAT, only very large retail ISPs need more than one
>>>>> announcement for IPv4.
>>>> 
>>>> 
>>>> You can only have about 200-300 subscribers per IPv4 address on a CGN. If you try to go further than that, for example by using symmetric NAT, you will increase the number of customers that want to get a public IPv4 of their own. That will actually decrease the combined efficiency and cause you to need more, not less, IPv4 addresses.
>>>> 
>>>> Without checking our numbers, I believe we have at least 10% of the customers that are paying for a public IPv4 to escape our CGN. This means a /24 will only be enough for about 2500 customers maximum. The "nat escapers" drown out the efficiency of the NAT pool.
>>>> 
>>>> The optimization you need to do is to make the CGN as customer friendly as possible instead of trying to squeeze the maximum customers per CGN IPv4 address.
>>>> 
>>>> Perhaps IPv6 can lower the number of people that need to escape IPv4 nat. If it helps just a little bit, that alone will make implementing IPv6 worth it for smaller emerging operators. Buying IPv4 has become very expensive. Yes you can profit from selling a public IPv4 address to the customer, but there is also the risk that the customer just goes to the incumbent, which has old large pools of IPv4 and provides it for free.
>>>> 
>>>> Regards,
>>>> 
>>>> Baldur
>>>> 
>> 
>> --
>> Mark Andrews, ISC
>> 1 Seymour St., Dundas Valley, NSW 2117, Australia
>> PHONE: +61 2 9871 4742              INTERNET: marka at isc.org
>> 

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka at isc.org