there is something in my head that drives me crazy .
let’s suppose that a internet service provider has the following IP address range:
41.96.0.0 to 41.111.255.255 that give him 1048576 IP Address for clients.
Now the crazy thing that i want to understand, i know that every machine has a unique ip address and it’s impossible to find two machines with one ip address (please correct me if i am wrong ) ; but this internet service provider has about 3,000,000 clients and every client has a unique ip ! how do they do it ? how do they provide all of these clients unique ip addresses ?
it’s logical that num clients = number of addresses
Until recently, service providers would simply justify their IP address needs to one of the 5 worldwide regional IP address registries by documenting how many customers they had and how many IP addresses each customer required (generally just 1 each for residential, but potentially more) and the registry would allocate to them as many as were needed. In IPv4, this is not true any longer, because the supply of IPv4 addresses is exhausted. ISPs and the 5 regional IP address registries are currently scraping the bottom of the IPv4 barrel.
When there are no more IPv4 addresses left to assign, ISPs will be forced to use NAT (Network Address Translation) to place more than one customer on each IP address. Mobile ISPs by and large have already been putting their customers behind NAT for years. End users have been doing it for even longer in order to be able to connect more than one device behind consumer-grade Internet connections that come with only one IPv4 address.
In IPv6 the number of available IP addresses is not expected to be a problem for the entire lifetime of the protocol.