Azure Classroomnotes 30/Jan/2023

CIDR Notation

• CIDR (Classless interdomain Routing)
• The ip addressing is mentioned as x.x.x.x/n

x.x.x.x => ip 
n = fixed bits

• Examples

10.10.10.0/24
ip: 10.10.10.x
SM: 11111111.11111111.11111111.00000000
    255.255.255.0
      2^n - 2
Size: 2^(32-24) - 2  => 254

10.10.10.0/23

ip: 10.10.0000101x.xxxxxxxx  => 10.10.10.x 10.10.11.x

SM: 11111111.11111111.11111110.00000000

Size: 2^(32-23) - 2  => 510


192.168.0.0/20

IP: 192. 168.         0000xxxx.xxxxxxxx
SM: 11111111.11111111.11110000.00000000

192.168.0.x to 192.168.15.x

Size: 2^(32-20) - 2  => 4094

CIDR: 172.16.0.0/12

IP: 172.     0001xxxx.xxxxxxxx.xxxxxxxx
SM: 11111111.11110000.00000000.00000000

Size: 2^(32-12) - 2  => 1048574

172.16.0.0 172.31.255.255


CIDR: 10.128.0.0/22
      10.128.         000000xx.xxxxxxxx
SM: 11111111.11111111.11111100.00000000
    10.128.0.0 to 10.128.3.255

10.128.0.0/10
IP        10.10xxxxxx.xxxxxxxx.xxxxxxxx
SM: 11111111.11000000.00000000.00000000

10.128.0.0 to 10.191.255.255


192.168.224.0/20
IP:           192.168.1110xxxx.xxxxxxxx
SM: 11111111.11111111.11110000.00000000
    192.168.224.0 to 192.168.239.255