Think it through · Start with a story
A girl gives every card a fixed-length number. As the number of cards grows, the supply of possible numbers does not grow with it.
Break down the process
- IPv432 bits
- Theoretical combinations2 to the power of 32
- Reserved usesNot all are available for public devices
- Ways to expandIPv6 and more
IPv4 has about 4.3 billion theoretical combinations, but some address ranges are reserved for special uses.
Demand from devices and networks around the world keeps growing, while the supply of public IPv4 resources is limited. Address sharing technologies help ease the pressure, and IPv6 provides a much larger address space.
This explains a long-term limit; it does not treat any region’s current inventory as a fact that will never change.
Your turn to try
If we make the digits in IPv4 addresses smaller on screen, will the total number of addresses increase?
Have you decided? Open to see the explanation
No. The limit comes from the number of combinations representable with 32 bits, not from how much screen space the digits take up.
Take away one discovery
IPv4 has about 4.3 billion theoretical combinations, but some address ranges are reserved for special uses.
Try covering the diagram and explaining each step to someone at home. If one step is unclear, go back and look at that card again.