Now the Internet architecture uses two versions of the protocol: IPv4, consisting of a 32-bit number, and IPv6, consisting of a 128-bit number. 32 bits in the fourth version allow you to use about 4 billion IP addresses, but even this amount is not enough for the Internet, which led to the emergence of IPv6. Another reason for its appearance is the hierarchical nature of addresses, which simplifies routing.
Why do we need a network prefix?
The aggregation size is set by the prefix length. Aggregation is the process of combining small prefixes with a long mask and a small number of hosts into large prefixes with a short mask and many hosts. Aggregation is needed to minimize the data required by the router when searching for a network path.
For example, 192.50.128.0/17 defines the first 17 bits of an IP address to identify address aggregation. The remaining 15 bits can be either sub-aggregated or assigned to devices in the network to which the prefix belongs.
One device can obtain an IP address from the range 192.50.128.0-192.50.255.255.