IP Subnet Calculator

IP Subnet Calculator Overview

We created two tools in the IP Subnet calculator, Subnet Details and Generate Subnet.

Subnet Details

This subnet calculator inputs a CIDR range and generates parameters such as host range, the usable host range, Gateway IP address, Broadcast IP address, Subnet Mask, and Network Mask (Mask Bits).

Generate Subnet

This IP subnet calculator generates equal-sized subnets for a given Random IP address, the number of subnets to generate, and the host bits. This simplifies the subnet calculations that otherwise need to be done manually.

Subnetting Terminology

CIDR Notation (Classless Inter Domain Routing)

CIDR (Classless Inter Domain Routing) range is a notation used to represent an IP address range more flexibly and efficiently than traditional IP address classes. CIDR notation is used to specify the network prefix and the number of significant bits in the subnet mask. This notation helps network administrators to allocate IP addresses more and manage IP address ranges.

CIDR notation consists of an IP address followed by a forward slash and a number indicating the number of bits in the subnet mask.

Gateway IP

The Gateway IP address is the default gateway through which the internet traffic is routed between the local and other networks. It works as an entry and exit point for the data packets.

Broadcast Address

As the name suggests, A broadcast address is used to send broadcast messages to all devices in the subnet. The Broadcast address is generally the last in the subnet address space.

Network Address

A network address is nothing but the IP address assigned to each device in the network to facilitate communication. A network address consists of the network ID and the host ID. The network ID identifies the specific network to which a device is connected, while the host ID identifies a host identifier or specific device within that network.

Subnet Masks

A subnet mask is a 32-bit number that divides an IP address into the network and hosts portions. The subnet mask identifies which part of the IP address represents the network, and the subnet bits show which part represents the host.

For example, a subnet mask of 255.255.255.0 indicates that the first 24 bits of the IP address represent the network part, and the remaining 8 bits represent the host part.

Wildcard Masks

A wildcard mask is a 32-bit number used in network routing and access control lists (ACLs) to specify which parts of an IP address should be matched or ignored.

IP Address Classes

IP class categorizes IP addresses into one address and five classes.

Class A

Class A IP addresses use the first octet to identify the network, with the remaining three octets (Prefix length is 8 bits) used to identify the number of hosts used on that network. The network ID ranges from 1.0.0.0 to 126.0.0.0 for the class A space. Class A addresses are designed for large organizations with many hosts.

Class B

Class B addresses use the first two octets to identify the network, with the remaining two octets (Prefix length is 16 bits) used to identify hosts on that network. The first two bits of a network Class- B address are always 10, and the network ID ranges from 128.0.0.0 to 191.255.0.0. Class B addresses are designed for medium-sized organizations.

Class C

Class C addresses use the first three octets to identify the network, with the remaining octet (Prefix length is 24 bits) used to identify hosts on that network. The first three bits of a Class C address are always 110, and the network ID ranges from 192.0.0.0 to 223.255.255.0. Class C addresses are designed for small-sized organizations.