CIDR - Classless Inter-Domain Routing
Short for Classless Inter-Domain Routing, an IP addressing scheme that replaces the older system based on classes A, B, and C. With CIDR, a single IP address can be used to designate many unique IP addresses. 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.For example:
The IP network prefix specifies how many addresses are covered by the CIDR address, with lower numbers covering more addresses. An IP network prefix of /12,for example, can be used to address 1,048,576 former Class C addresses.
CIDR addresses reduce the size of routing tables and make more IP addresses available within organizations.
CIDR is also called supernetting.
From secure messaging to document editing, our top free must-have apps have been rated, reviewed and named the best free Android apps of 2015. Read More »The Five Generations of Computers
Learn about each of the five generations of computers and major technology developments that have led to the current devices that we use today. Read More »Cloud Computing Market Leaders, 2015
If not for AWS, Microsoft would dominate the cloud. The race to capture market share will grow ever more fierce in the years ahead. Here's a look... Read More »
From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »Network Fundamentals Study Guide
A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »Computer Architecture Study Guide
This Webopedia study guide describes the different parts of a computer system and their relations. Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »