Question:

How many IPv4 addresses are used for dynamic assignment through ISPs?

Melody: 02 February 2022

From the IPv4 addresses, we have the private addresses (10.x, 172.x, 192.x), localhost addresses (127.x), self-assigned (169.x) multicast and broadcast addresses.

From the remaining, I guess a lot of addresses are assigned to large companies, use for web servers etc.

How many IPv4 addresses (roughly) are used for dynamic assignment by ISPs to users for dial-in connections like DSL router etc.?

Answer:
Emilia: 02 February 2022

ISP's are just like large companies that are assigned IP addresses. They can decide how many of their customers have a dedicated IP address and how many have dynamic IP. For example in Romania you have to pay for static IP in most ISP's. Even ISP's that provide home connection of 1 GBPS do not give you static IP by default. So many customers can connect through the same IP at different times.

Here is a list with some companies that have been assigned IP addresses by IANA. In other countries is the same. There are some companies and ISPs that have IPs and than they assign them to customers statically or dynamically or sell them / rent them to other companies.