CIDR Notation

CIDR stands for Classless Inter-Domain Routing. CIDR was developed in the 1990s as a standard scheme for routing network traffic across the Internet.


/27      1/8th of a Class C     32 hosts
/26      1/4th of a Class C     64 hosts
/25      1/2 of a Class C       128 hosts
/24      1 Class C              256 hosts
/23      2 Class C              512 hosts
/22      4 Class C              1,024 hosts
/21      8 Class C              2,048 hosts
/20      16 Class C             4,096 hosts
/19      32 Class C             8,192 hosts
/18      64 Class C             16,384 hosts
/17      128 Class C            32,768 hosts
/16      256 Class C            65,536 hosts (= 1 Class B)
/15      512 Class C            131,072 hosts
/14      1,024 Class C          262,144 hosts
/13      2,048 Class C          524,288 hosts

 
 
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darkstat

http://unix4lyfe.org/darkstat/

darkstat is an ntop-workalike network statistics gatherer. It runs as a background process on a cable or DSL router, uses libpcap to capture network traffic, and has a Web interface that serves up reports of statistics such as data transferred by host, port, and protocol. It also has a neat bandwidth usage graph.

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