CIDR to IPV4 Conversion

CIDR is the short for Classless Inter-Domain Routing, an IP addressing scheme that replaces the older system based on classes A, B, and C. A single IP address can be used to designate many unique IP addresses with CIDR. A CIDR IP address looks like a normal IP address except that it ends with a slash followed by a number, called the IP network prefix. CIDR addresses reduce the size of routing tables and make more IP addresses available within organizations. Please try out our CIDR calculator below.

What is CIDR?

CIDR, which stands for Classless Inter-Domain Routing, is a method for allocating IP addresses and routing Internet Protocol packets. It was introduced to improve the allocation of IP addresses and the efficiency of routing compared to the older classful network addressing method.

Here are some key points about CIDR:

  • Efficient IP Address Utilization: CIDR allows for a more flexible distribution of IP addresses by varying the length of the subnet mask. This leads to more efficient usage of a limited number of IP addresses.
  • Subnet Masks: In CIDR, the IP address is followed by a slash (/) and a number, which represents the subnet mask. For example, in the CIDR notation 192.168.0.0/24, the "/24" indicates that the first 24 bits of the IP address are used for network addressing, and the remaining bits are used for host addresses.
  • Supernetting and Aggregation: CIDR supports supernetting, which means combining multiple networks into a single network. This is used for IP routing aggregation, which reduces the size of routing tables and improves the efficiency of Internet routing.
  • Eliminates Classes: Traditional classful IP addressing divided the IP address space into five classes (A, B, C, D, E). CIDR removes these classes and allows for a more granular allocation of addresses.
  • IPV4 and IPV6: CIDR is used in both IPv4 and IPv6 addressing. In IPv6, due to its larger address space, CIDR plays a crucial role in address allocation and routing.

CIDR has been crucial in extending the life of IPv4 by allowing more efficient use of its limited address space and is fundamental to the way IP addresses are managed and routed on the Internet.