The Ipv4/Ipv6 CIDR Calculator tool can convert Ipv4 CIDR addresses or Ipv6 CIDR addresses into IP ranges. It helps calculate the first and last IP addresses in the CIDR range, the number of IP addresses in the CIDR, subnet ranger and wildcard (in Ipv4 CIDR), abbreviated address and unabbreviated address (in Ipv6 CIDR).
What is an CIDR
- CIDR, short for Classless Inter Domain Routing, is an IP addressing scheme that improves IP address allocation. CIDR replaces the old system based on classes A, B and C. CIDR IP address looks like a normal IP address except that it ends with a slash followed by a number, called a prefix. CIDR addresses reduce the size of routing tables and provide additional IP addresses.
- The CIDR IP address consist of two sets of numbers. The network address is written as a prefix, as you will see at a normal IP address (for example, Ipv4 18.104.22.168, Ipv6 2002:ab8::). The second part is the suffix that indicates how many bits are there in the entire address (0-32 for Ipv4 and 0-128 for Ipv6, for example /16). Putting these 2 parts together, a CIDR IP address will look like this: CIDR Ipv4 : 22.214.171.124/16 , CIDR Ipv6 : 2002:ab8::/16
What is CIDR used for?
CIDR provides a supernetting mechanism, an improvement to route collection. As the Internet grows bigger and bigger, routers require huge storage tables to store all routing information. Supernetting shortens and combines multiple routing information into a single entry, thereby reducing the size of the router's storage tables and speeding up the search process.