Classful Networking
CIDR
- This stands for Classless Inter-Domain Routing
ip : 192.168.0.100
SM : 255.255.255.0
: 11111111.11111111.11111111.00000000 => 192.168.0.100/24
cidr: 192.168.0.0/23
SM : 11111111.11111111.11111110.00000000
255.255.254.0
hosts => 2^9-2 => 512-2 = 510
cidr: 192.168.0.0/25
SM: 11111111.11111111.11111111.10000000
255.255.255.128
hosts => 2^7-2 = 128-2 = 126
- I want to create a network for my organization which should have 5000 devices. Can you suggest the Subnet Mask
total number of devices ~= 5000
2^n-2 ~= 5000
2^n ~= 5000
n=13
x.x.x.x/19
11111111.11111111.11100000.00000000
255.255.224.0
- Now lets try to create a network which can host upto 25000 devices
2^n ~= 25000
n=15
cidr => x.x.x.x/(32-15) => x.x.x.x/17
SM: 11111111.11111111.10000000.00000000
SM: 255.255.128.0
-
Convention of Public Networks and Private Networks
- Public Networks are ip addresses which are accessible over internet
- Private networks are for private usage & there are some reserved ip ranges for private networking.
-
In all the clouds and in the enterprise when we configure networking its always private network. so we will be choosing the ip range from
- 192.168.0.0/16
- 10.0.0.0/8
- 172.16.0.0/12
- Now lets learn to expand the cidr notation to find the range of ip addresses possible
192.168.0.0/16 => 192.168.0.0 - 192.168.255.255 => 65000
192.168.0.0/24 => 192.168.0.0 - 192.168.0.255
=> 255
- Note: Creating Azure Account Refer Here
