CIDR

• Expand the CIDR Range

10.224.0.0/11

fixed = 11
variable = 32-11 = 21

IP:       10.111xxxxx.xxxxxxxx.xxxxxxxx
SM: 11111111.11100000.00000000.00000000

Range: 10.224.0.0 to 10.255.255.255

Subnet

• Subnet is part of network
• As a cloud engineer we are expected to create networks and multiple subnets

Problem-1: We need to design network with two subnets of size approximately 200 devices

• Each subnet = 200
• network = 400

private: 
    192.168.0.0/16
    172.16.0.0/12
    10.0.0.0/8

Network

2^v ~= 400
variable = 9
Fixed = 32-9 = 23

ip:            172.16.0000000x.xxxxxxxx => 172.16.0.0/23
SM: 11111111.11111111.11111110.00000000

Subnet 
2^v ~= 200
variable = 8
fixed = 24

ip                    172.16.0.xxxxxxxx  => 172.16.0.0/24
SM: 11111111.11111111.11111111.00000000

ip                    172.16.1.xxxxxxxx  => 172.16.1.0/24
SM: 11111111.11111111.11111111.00000000

• Network cidr: 172.16.0.0/23
• Subnet 1 cidr: 172.16.0.0/24
• subnet 2 cidr: 172.16.1.0/24

Problem-2: Create 4 subnets with 100 devices each in network

• Each subnet = 100
• network = 400

Network

2^v ~= 400
variable = 9
fixed = 23

ip: 192.168.0.0/23

SM: 11111111.11111111.1111111x.xxxxxxxx

Subnet:

2^v ~=100
variable = 7
fixed = 25

Network SM: 11111111.11111111.1111111x.xxxxxxxx
Subnet  SM: 11111111.11111111.11111111.1xxxxxxx
------------------------------------------------
                                     y.y
                      192.168.00000000.0xxxxxxx => 192.168.0.0/25
                      192.168.00000000.1xxxxxxx => 192.168.0.128/25
                      192.168.00000001.0xxxxxxx => 192.168.1.0/25
                      192.168.00000001.1xxxxxxx => 192.168.1.128/25

Problem 3: Create 4 subnets of size 50

• Network size ~= 200
• subnet size ~=50

Network

2^v ~= 100
variable = 8
fixed = 24

ip: 192.168.0.0/23

SM: 11111111.11111111.1111111x.xxxxxxxx

Subnet:

2^v ~=50
variable = 6
fixed = 26

Network SM: 11111111.11111111.11111111.xxxxxxxx
Subnet  SM: 11111111.11111111.11111111.11xxxxxx
------------------------------------------------
                                       yy
                             192.168.0.00xxxxxx => 192.168.0.0/26
                             192.168.0.01xxxxxx => 192.168.0.64/26
                             192.168.0.10xxxxxx => 192.168.0.128/26
                             192.168.0.11xxxxxx => 192.168.0.192/26

Exercises

• Create a netowork with
  • 8 subnets of size 500 each
  • 6 subnets of size 300 each