What is CIDR - Classless Inter-domain Routing?

johnny_jiang

Some texts use the term CIDR synonymously with the term route summarization. Others use the term CIDR to refer to the process of summarizing multiple classful networks together. In other cases, when an ISP assigns subsets of a classful network to a customer who does not need an entire class C network, the ISP is essentially performing subnetting; once again, this idea sometimes gets categorized as CIDR.
But CIDR itself refers to the administrative assignment of large address blocks, and the related summarized routes, for the purpose of reducing the size of the Internet routing tables.
NOTE: Because CIDR defines how to combine routes for multiple classful networks into a single route, some people think of this process as being the opposite of subnetting. As a result, many people refer to CIDR’s summarization results as supernetting.
               
               
               

本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u1/42903/showart_1006885.html