This calculator offers a variety of information on IPv4 and IPv6 subnets, such as feasible network addresses, usable host ranges, subnet masks, and IP classes.
A subnet is a subset of an IP network (Internet protocol suite), a collection of communication protocols used on the Internet and comparable networks. It is frequently referred to as TCP/IP (Transmission Control Protocol/Internet Protocol).
Subnetting is the process of splitting a network into at least two independent networks, and routers are devices that allow traffic to flow between subnetworks while also acting as a physical boundary. IPv4 is the most commonly used network addressing scheme. However, IPv6 adoption has increased since 2006.
An IP address consists of a network number (routing prefix) and a rest field (host identifier). A rest field is an identifier unique to a particular host or network interface. Classless Inter-Domain Routing (CIDR) notation is commonly used to represent routing prefixes for both IPv4 and IPv6. CIDR is a means of creating unique IDs for both networks and individual devices. For IPv4, networks can also be defined via a subnet mask, which is sometimes represented in dot-decimal notation, as displayed in the calculator's "Subnet" field. All hosts on a subnetwork have the same network prefix, as opposed to the host identifier, which is a unique local identity. In IPv4, subnet masks are used to distinguish between network numbers and host identifiers. In IPv6, the network prefix serves the same purpose as the subnet mask in IPv4, with the prefix length indicating the number of bits in the address.
Prior to the advent of CIDR, IPv4 network prefixes could be derived directly from IP addresses using the address's class (A, B, or C, which varies depending on the range of IP addresses it contains) and network mask. Since the introduction of CIDRs, however, assigning an IP address to a network interface necessitates both the address and the network mask.