MultiCloud Classroom notes 22/Feb/2024

Networking contd

I want to create a private network for 100 devices

• private ip ranges:
  • 192.168.0.0 to 192.168.255.255
  • 10.0.0.0 to 10.255.255.255
  • 172.16.0.0 to 172.31.255.255
• ip address:
  • fixed: network id
  • variable: host id
• network size: dependent on variable size i.e. bits for host id

size: 2^n - 2 

• In this case

100 = 2^n-2
100 ~= 2^n 

n (host id bits) = 7
N (network id bits) = 32 - 7 = 25

SM: 11111111.11111111.11111111.10000000

• Now i need to choose a private ip

ip:  192.168.0                 .0xxxxxxx
min: 192.168.0                 .00000000 = 192.168.0.0
max: 192.168.0                 .01111111 = 192.168.0.127
SM:  11111111.11111111.11111111.10000000

I want to create a private network for 100000 devices

• network size

2^n ~= 100000
n (variable/host id) = 17
N (fixed/network) = 32 - 17 = 15

ip:       172.0001000x.xxxxxxxx.xxxxxxxx
min:      172.00010000.00000000.00000000 = 172.16.0.0
max:      172.00010001.11111111.11111111 = 172.17.255.255
SM:  11111111.11111110.00000000.00000000

I want to create a private network of 2000 devices

• network size and range

2^n ~= 2000
n  = 11
N  = 32 - 11 = 21
ip:               10.0.00000xxx.xxxxxxx
min:              10.0.00000000.0000000 = 10.0.0.0
max:              10.0.00000111.1111111 = 10.0.7.255
SM:  11111111.11111111.11111000.00000000

Exercise:

• Create a private network of size
  • 5000 devices
  • 50 devices
  • 60000 devices
• 5000 devices

2^n ~= 5000
n = 13
N = 32 - 13 = 19

ip:            192.168.000xxxxx.xxxxxxxx
min:           192.168.00000000.00000000 = 192.168.0.0
max:           192.168.00011111.11111111 = 192.168.31.255
SM:  11111111.11111111.11100000.00000000

• 50 devices

2^n ~= 50
n = 6
N = 32 - 6 = 26

ip:                   10.100.0.00xxxxxx
min:                  10.100.0.00000000 = 10.100.0.0
max:                  10.100.0.00111111 = 10.100.0.63
SM: 11111111.11111111.11111111.11000000

• 60000 devices

2^n ~= 600000
n = 16
N = 16
ip:           192.168.xxxxxxxx.xxxxxxxx = 192.168.0.0 to 192.168.255.255
SM: 11111111.11111111.00000000.00000000

CIDR Notation

• This is an expression to indicate the network range

x.x.x.x/N
x.x.x.x => ip generally start ip
N = number of fixed bits i.e. network id bits

• examples

192.168.0.0/16
10.100.0.0/26
192.168.0.0/19

• private ip cidr ranges

10.0.0.0/8
172.16.0.0/12
192.168.0.0/16

Expand a CIDR range

• 192.168.0.0/25

N = 25 

ip:                  192.168.0.0xxxxxxx
min:                 192.168.0.00000000 = 192.168.0.0
min:                 192.168.0.01111111 = 192.168.0.127
SM: 11111111.11111111.11111111.10000000

• 192.168.128.0/17

N = 17
n = 15

ip:           192.168.1xxxxxxx.xxxxxxxx
min:          192.168.10000000.00000000 = 192.168.128.0
max:          192.168.11111111.11111111 = 192.168.255.255
SM: 11111111.11111111.10000000.00000000

• 10.0.0.0/27

ip:                      10.0.0.000xxxxx
min: 10.0.0.0
max:                     10.0.0.00011111 = 10.0.0.31
SM:  11111111.11111111.11111111.11100000