The IPv6 Subnet Calculator performs network calculations on the given network address block, routing prefix and determines subnet address, host range and notation for the subnet.
Subnetting
There comes a time when a network becomes too large to manage and performance numbers hit the low as a result of too much traffic. One of the most effective technique to solve this network congestion problem is to break the TCP/IP network into smaller, more manageable pieces. The practice of dividing the network is called subnetting.