IPv4 Address in CIDR Range Tool

Check if an IP address is in a CIDR range

You can use this tool to determine whether any given IP Address (in IPv4 format) is a part of a specified CIDR notation range.  It also helps to determine whether or not a specific IP v4 address is within a given range. 

Use this tool to evaluate testing the IP address presence without any complicated calculations or reasoning. 

How to determine an IP address is in a specific range.

1. Input a valid IP address in IPv4 format with the CIDR notation range
2. Input a valid IP address in IPv4 format with the CIDR notation range
3. Click 'Check' to determine if it belongs to the range or not.
4. For instance, to test it, enter the IP address 192.168.0.1 and the CIDR range 192.168.0.0/24 to confirm that it’s in the range.

IPv4 subnet calculator

The IPv4 subnet calculator divided the IP into the various components - network address, subnet mask, broadcast address, and host IP address range to IP network into subnetworks. The Cisco wildcard mask is the inverted network mask used in Cisco routers for access control lists (ACLs).

To calculate an enter the IP address, choose a prefix length and click "Get IP Info".
The information, such as usable host address,start and end IP range, and total IPs will be displayed.
 

To check if an IP address range is within a CIDR range

You can follow these steps:

1. Parse the CIDR range into its network address and subnet mask.
   The CIDR range consists of an IP address and a suffix indicating the subnet mask length. For example, 192.168.0.0/24 means the network address is 192.168.0.0, and the subnet mask is 24 bits long.
2. Calculate the network and broadcast addresses of the IP address range you want to check.
   Given an IP address range, determine the lowest (network address) and highest (broadcast address) IP addresses within that range.
3. Determine if the network and broadcast addresses of the IP address range you want to check fall within the CIDR range.
   Compare the network address and broadcast address with the network address and subnet mask obtained from the CIDR range. If both the network address and broadcast address are within the CIDR range, then the IP address range is also within the CIDR range.

IP Class Address Range

• Class A - 1.0.0.1 to 126.255.255.254 (supports 16 million hosts on each of 127 networks).
• Class B - 128.1.0.1 to 191.255.255.254 (65,000 hosts on each of 16,000 networks).
• Class C - 192.0.1.1 to 223.255.254.254 (254 hosts on each of 2 million networks).
• Class D - 224.0.0.0 to 239.255.255.255 (address range reserved for multicast groups).
• Class E - 240.0.0.0 to 254.255.255.254 (reserved for future use, research and development purposes).

Subnet Mask Definition

Every device has two IP addresses: one for the client or host and one for the server or network. A DHCP server or a manual configuration is used to assign IP addresses (static IP addresses).

The subnet mask divides an IP address into the host and network addresses, indicating which portion belongs to the device and the network. A gateway, sometimes known as a default gateway, is a device that links local devices to external networks.

When a local device wishes to transfer data to a device with an IP address on another network, it sends its packets to the gateway, relaying the data to its destination outside the local network.

CIDR Subnet Mask Notation

When translated to binary, the CIDR number originates from the number of ones in the subnet mask.

The number of bits available to the IP address is represented by the CIDR notation, which is essentially just shorthand for the subnet mask.
For example, the/24 in 192.168.0.101/24 corresponds to the IP address 192.168.0.101 with the subnet mask 255.255.255.0.

Compared to the traditional Classful addressing scheme, the CIDR IP addressing system allows for more flexible IP address allocation (A, B, C, D, and E). The Classful IP addressing system may be inefficient. It gives a network that only requires 15 IP addresses the minimum IP address allocation of 256 (Class C).

In 1993, CIDR was established to reduce the use of IPv4 addresses, which were quickly running out under the previous Classful IP addressing system that the internet was built on.

In IPv4 and, more recently, IPv6 routing, CIDR is employed. When setting addresses and networks, it is advised to use CIDR (Classless Inter-Domain Routing) notation rather than the usual subnet mask 255.x.x.x.x when configuring addresses and networks.