I have written this answer as simply as I know how. I have left out some details, of course, and generalized the answer for a clearer answer.
Every entity that requires IP addresses is allocated a range of IP addresses generally one of two ways. One, are larger entities that are allocated large blocks of IP addresses. Second, are smaller entities that are allocated IP addresses from the larger blocks of the larger entities as customers. This can be be several levels deep. For example, CenturyLink IP addresses are allocated from Quest. Quest is allocated from Level 3 Communications which is a Tier 1 provider. If you operate a web hosting operation with a link to the Internet provided by CenturyLink, then CenturyLink allocates a block of IP addresses to your operation.
Backing up a bit, Internet Assigned Numbers Authority (IANA) is responsible for all IP address allocations through one of the five regional Internet registry (RIR):
- African Network Information Center (AFRINIC) for Africa
- American Registry for Internet Numbers (ARIN) for the United
States, Canada, several parts of the Caribbean region, and
Antarctica.
- Asia-Pacific Network Information Centre (APNIC) for Asia,
Australia, New Zealand, and neighboring countries
- Latin America and Caribbean Network Information Centre (LACNIC)
for Latin America and parts of the Caribbean region
- Réseaux IP Européens Network Coordination Centre (RIPE NCC) for
Europe, Russia, the Middle East, and Central Asia
Because Level 3 Communications is a large Tier 1 provider, it operates an Internet backbone network and gets it's IP address allocation from American Registry for Internet Numbers (ARIN). Quest is a commercial and subscriber telecommunications provider, so is CenturyLink as a subsidiarity of Quest. This means that Quest gets it's allocation from Level 3, and CenturyLink from Quest.
All IP addresses are either static or dynamic. This is determined by the company that holds the allocation. For example, web hosting companies use static IP addresses as this is generally required for the web. However, those with DSL lines (known as subscriber lines) from their telecommunications company (phone) will more likely have dynamic IP addresses. There is no one block of IP addresses for static or dynamic. Each block provided as subscriber blocks are generally huge while for large scale services companies such as the web hosting provider RackSpace is also huge. As well, companies that range from IBM, HP, Google, etc., can also have huge blocks of IP addresses.
In short, there is no simple way of determining static IP address blocks and dynamic IP address blocks. There are ways, but nothing we can describe here easily enough to help. It gets technical really fast.
As for dynamic IP addresses, these are issued using a lease method known as DHCP. With DHCP, a computer or router, for example, would request an IP address. This IP address once assigned is said to be leased. A lease through DHCP depends upon the parameters the DHCP system was set up with. Leases can be long or short. If a computer disconnects and reconnects, depending upon the lease period, it is highly likely that it will receive the same IP address as before. This is how things normally work. However, this is not a given. Some DHCP systems will issue a new IP from the pool with every connection. This is often the first IP address within the pool that is available which can be the same IP address or not depending upon the allocation activity.
So it gets complicated as you can see. I will not get into the weeds here. This should give you a good idea of how things work.
