Prior to the introduction of CIDR, IPv4 network prefixes could be directly obtained from the IP address based on the class (A, B, or C, which vary based on the range of IP addresses they include) of the address and the network mask. In IPv6, the network prefix performs a similar function as the subnet mask in IPv4, with the prefix length representing the number of bits in the address. In IPv4, these subnet masks are used to differentiate the network number and host identifier. All hosts on a subnetwork have the same network prefix, unlike the host identifier, which is a unique local identification. For IPv4, networks can also be characterized using a subnet mask, which is sometimes expressed in dot-decimal notation, as shown in the 'Subnet' field in the calculator. CIDR is a method used to create unique identifiers for networks, as well as individual devices. A routing prefix is often expressed using Classless Inter-Domain Routing (CIDR) notation for both IPv4 and IPv6.

A rest field is an identifier that is specific to a given host or network interface. IPv4 is the most common network addressing architecture used, though the use of IPv6 has been growing since 2006.Īn IP address is comprised of a network number (routing prefix) and a rest field (host identifier).

The act of dividing a network into at least two separate networks is called subnetting, and routers are devices that allow traffic exchange between subnetworks, serving as a physical boundary. It is commonly known as TCP/IP (Transmission Control Protocol/Internet Protocol). Related Bandwidth Calculator | Binary CalculatorĪ subnet is a division of an IP network (internet protocol suite), where an IP network is a set of communications protocols used on the Internet and other similar networks.

Subnetting chart