Class A Networks:

21.0.0.0-(Owner) | 21.1.0.0-(Owner) | 21.2.0.0-(Owner) | 21.3.0.0-(Owner) | 21.4.0.0-(Owner) | 21.5.0.0-(Owner) | 21.6.0.0-(Owner) | 21.7.0.0-(Owner) | 21.8.0.0-(Owner) | 21.9.0.0-(Owner) | 21.10.0.0-(Owner) | 21.11.0.0-(Owner) | 21.12.0.0-(Owner) | 21.13.0.0-(Owner) | 21.14.0.0-(Owner) | 21.15.0.0-(Owner) | 21.16.0.0-(Owner) | 21.17.0.0-(Owner) | 21.18.0.0-(Owner) | 21.19.0.0-(Owner) | 21.20.0.0-(Owner) | 21.21.0.0-(Owner) | 21.22.0.0-(Owner) | 21.23.0.0-(Owner) | 21.24.0.0-(Owner) | 21.25.0.0-(Owner) | 21.26.0.0-(Owner) | 21.27.0.0-(Owner) | 21.28.0.0-(Owner) | 21.29.0.0-(Owner) | 21.30.0.0-(Owner) | 21.31.0.0-(Owner) | 21.32.0.0-(Owner) | 21.33.0.0-(Owner) | 21.34.0.0-(Owner) | 21.35.0.0-(Owner) | 21.36.0.0-(Owner) | 21.37.0.0-(Owner) | 21.38.0.0-(Owner) | 21.39.0.0-(Owner) | 21.40.0.0-(Owner) | 21.41.0.0-(Owner) | 21.42.0.0-(Owner) | 21.43.0.0-(Owner) | 21.44.0.0-(Owner) | 21.45.0.0-(Owner) | 21.46.0.0-(Owner) | 21.47.0.0-(Owner) | 21.48.0.0-(Owner) | 21.49.0.0-(Owner) | 21.50.0.0-(Owner) | 21.51.0.0-(Owner) | 21.52.0.0-(Owner) | 21.53.0.0-(Owner) | 21.54.0.0-(Owner) | 21.55.0.0-(Owner) | 21.56.0.0-(Owner) | 21.57.0.0-(Owner) | 21.58.0.0-(Owner) | 21.59.0.0-(Owner) | 21.60.0.0-(Owner) | 21.61.0.0-(Owner) | 21.62.0.0-(Owner) | 21.63.0.0-(Owner) | 21.64.0.0-(Owner) | 21.65.0.0-(Owner) | 21.66.0.0-(Owner) | 21.67.0.0-(Owner) | 21.68.0.0-(Owner) | 21.69.0.0-(Owner) | 21.70.0.0-(Owner) | 21.71.0.0-(Owner) | 21.72.0.0-(Owner) | 21.73.0.0-(Owner) | 21.74.0.0-(Owner) | 21.75.0.0-(Owner) | 21.76.0.0-(Owner) | 21.77.0.0-(Owner) | 21.78.0.0-(Owner) | 21.79.0.0-(Owner) | 21.80.0.0-(Owner) | 21.81.0.0-(Owner) | 21.82.0.0-(Owner) | 21.83.0.0-(Owner) | 21.84.0.0-(Owner) | 21.85.0.0-(Owner) | 21.86.0.0-(Owner) | 21.87.0.0-(Owner) | 21.88.0.0-(Owner) | 21.89.0.0-(Owner) | 21.90.0.0-(Owner) | 21.91.0.0-(Owner) | 21.92.0.0-(Owner) | 21.93.0.0-(Owner) | 21.94.0.0-(Owner) | 21.95.0.0-(Owner) | 21.96.0.0-(Owner) | 21.97.0.0-(Owner) | 21.98.0.0-(Owner) | 21.99.0.0-(Owner) | 21.100.0.0-(Owner) | 21.101.0.0-(Owner) | 21.102.0.0-(Owner) | 21.103.0.0-(Owner) | 21.104.0.0-(Owner) | 21.105.0.0-(Owner) | 21.106.0.0-(Owner) | 21.107.0.0-(Owner) | 21.108.0.0-(Owner) | 21.109.0.0-(Owner) | 21.110.0.0-(Owner) | 21.111.0.0-(Owner) | 21.112.0.0-(Owner) | 21.113.0.0-(Owner) | 21.114.0.0-(Owner) | 21.115.0.0-(Owner) | 21.116.0.0-(Owner) | 21.117.0.0-(Owner) | 21.118.0.0-(Owner) | 21.119.0.0-(Owner) | 21.120.0.0-(Owner) | 21.121.0.0-(Owner) | 21.122.0.0-(Owner) | 21.123.0.0-(Owner) | 21.124.0.0-(Owner) | 21.125.0.0-(Owner) | 21.126.0.0-(Owner) | 21.127.0.0-(Owner) | 21.128.0.0-(Owner) | 21.129.0.0-(Owner) | 21.130.0.0-(Owner) | 21.131.0.0-(Owner) | 21.132.0.0-(Owner) | 21.133.0.0-(Owner) | 21.134.0.0-(Owner) | 21.135.0.0-(Owner) | 21.136.0.0-(Owner) | 21.137.0.0-(Owner) | 21.138.0.0-(Owner) | 21.139.0.0-(Owner) | 21.140.0.0-(Owner) | 21.141.0.0-(Owner) | 21.142.0.0-(Owner) | 21.143.0.0-(Owner) | 21.144.0.0-(Owner) | 21.145.0.0-(Owner) | 21.146.0.0-(Owner) | 21.147.0.0-(Owner) | 21.148.0.0-(Owner) | 21.149.0.0-(Owner) | 21.150.0.0-(Owner) | 21.151.0.0-(Owner) | 21.152.0.0-(Owner) | 21.153.0.0-(Owner) | 21.154.0.0-(Owner) | 21.155.0.0-(Owner) | 21.156.0.0-(Owner) | 21.157.0.0-(Owner) | 21.158.0.0-(Owner) | 21.159.0.0-(Owner) | 21.160.0.0-(Owner) | 21.161.0.0-(Owner) | 21.162.0.0-(Owner) | 21.163.0.0-(Owner) | 21.164.0.0-(Owner) | 21.165.0.0-(Owner) | 21.166.0.0-(Owner) | 21.167.0.0-(Owner) | 21.168.0.0-(Owner) | 21.169.0.0-(Owner) | 21.170.0.0-(Owner) | 21.171.0.0-(Owner) | 21.172.0.0-(Owner) | 21.173.0.0-(Owner) | 21.174.0.0-(Owner) | 21.175.0.0-(Owner) | 21.176.0.0-(Owner) | 21.177.0.0-(Owner) | 21.178.0.0-(Owner) | 21.179.0.0-(Owner) | 21.180.0.0-(Owner) | 21.181.0.0-(Owner) | 21.182.0.0-(Owner) | 21.183.0.0-(Owner) | 21.184.0.0-(Owner) | 21.185.0.0-(Owner) | 21.186.0.0-(Owner) | 21.187.0.0-(Owner) | 21.188.0.0-(Owner) | 21.189.0.0-(Owner) | 21.190.0.0-(Owner) | 21.191.0.0-(Owner) | 21.192.0.0-(Owner) | 21.193.0.0-(Owner) | 21.194.0.0-(Owner) | 21.195.0.0-(Owner) | 21.196.0.0-(Owner) | 21.197.0.0-(Owner) | 21.198.0.0-(Owner) | 21.199.0.0-(Owner) | 21.200.0.0-(Owner) | 21.201.0.0-(Owner) | 21.202.0.0-(Owner) | 21.203.0.0-(Owner) | 21.204.0.0-(Owner) | 21.205.0.0-(Owner) | 21.206.0.0-(Owner) | 21.207.0.0-(Owner) | 21.208.0.0-(Owner) | 21.209.0.0-(Owner) | 21.210.0.0-(Owner) | 21.211.0.0-(Owner) | 21.212.0.0-(Owner) | 21.213.0.0-(Owner) | 21.214.0.0-(Owner) | 21.215.0.0-(Owner) | 21.216.0.0-(Owner) | 21.217.0.0-(Owner) | 21.218.0.0-(Owner) | 21.219.0.0-(Owner) | 21.220.0.0-(Owner) | 21.221.0.0-(Owner) | 21.222.0.0-(Owner) | 21.223.0.0-(Owner) | 21.224.0.0-(Owner) | 21.225.0.0-(Owner) | 21.226.0.0-(Owner) | 21.227.0.0-(Owner) | 21.228.0.0-(Owner) | 21.229.0.0-(Owner) | 21.230.0.0-(Owner) | 21.231.0.0-(Owner) | 21.232.0.0-(Owner) | 21.233.0.0-(Owner) | 21.234.0.0-(Owner) | 21.235.0.0-(Owner) | 21.236.0.0-(Owner) | 21.237.0.0-(Owner) | 21.238.0.0-(Owner) | 21.239.0.0-(Owner) | 21.240.0.0-(Owner) | 21.241.0.0-(Owner) | 21.242.0.0-(Owner) | 21.243.0.0-(Owner) | 21.244.0.0-(Owner) | 21.245.0.0-(Owner) | 21.246.0.0-(Owner) | 21.247.0.0-(Owner) | 21.248.0.0-(Owner) | 21.249.0.0-(Owner) | 21.250.0.0-(Owner) | 21.251.0.0-(Owner) | 21.252.0.0-(Owner) | 21.253.0.0-(Owner) | 21.254.0.0-(Owner) |

IP Address (Internet Protocol Address):

This number is an exclusive number all information technology devices (printers, routers, modems, et al) use which identifies and allows them the ability to communicate with each other on a computer network. There is a standard of communication which is called an Internet Protocol standard (IP).

Classless Inter-Domain Routing

(CIDR) is a methodology of allocating IP addresses and routing Internet Protocol packets. It was introduced in 1993 to replace the prior addressing architecture of classful network design in the Internet with the goal to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses.

Autonomous System

(AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators that presents a common, clearly defined routing policy to the Internet

IPv4:

Currently used by most network devices. However, with more and more computers accessing the internet, IPv4 IPs are running out quickly. Just like in a city, addresses have to be created for new neighborhoods but, if your neighborhood gets too large, you will have to come up with an entire new pool of addresses. IPv4 is limited to 4,294,967,296 IPs.