1. Supernet concept:
Supernetting, also known as Classless Inter-Domain Routing (CIDR). CIDR eliminates traditional Class A, Class B and Class C addresses and the concept of subnetting. CIDR uses "network prefixes" of various lengths to replace network numbers and subnet numbers in classified addresses. CIDR no longer uses the concept of "subnets" but uses network prefixes, so that IP addresses return from three-level addressing to two-level addressing, that is, two-level addressing without classification.
IP=network prefix+host number
2. Representation method:
CIDR also uses "slash notation", that is, write a slash "/" after the IP address, and then write the number of digits occupied by the network prefix (corresponding to the number of 1s in the subnet mask). For example: 192.168.1.0/22. The network prefix is 22 bits, which also means that the first 22 bits of the mask are 1
3. Function:
Merge several small networks belonging to an organization into a logical network with a larger address range.
That is, CIDR forms a "CIDR address block" of consecutive IP addresses with the same network prefix.