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.co...@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 <ma...@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.co...@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.nordd...@gmail.com> wrote: >>>> >>>> >>>> >>>> On Wed, 22 Sept 2021 at 16:48, Masataka Ohta >>>> <mo...@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: ma...@isc.org >> -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org
