Question

Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and routing Internet Protocol packets. Classless Inter-Domain Routing allocates address space to Internet service providers and end users on any address bit boundary, instead of on 8-bit segments. CIDR notation is a syntax of specifying IP addresses and their associated routing prefix. It appends a slash character to the address and the decimal number of leading bits of the routing prefix. 192.168.100.0/24 represents the given IPv4 address and its associated routing prefix 192.168.100.0, or equivalently, its subnet mask 255.255.255.0.

Given a CIDR address of 168.2.44.0/22, answer the following questions.

a) How many assignable IP addresses are there?
b) What is the assignable IP address range?
c) What is the subnet mask?

Useful Ref: https://www.ipaddressguide.com/cidr

Answer 1

a) since total address is 32 bit , so total host bit is=32-22=10 bit,

so assignable address is=2¹⁰-2=1022 [because first address is used for network address and last address is used for broadcast address]

b)assignable ip address range=168.2.44.0 to   168.2.47.255

c)subnet mask is= 255.255.252.0

because, if we represent subnet address in bit then,

168.2.44.0/22=0101100.00000010.00011100.00000000 [where last ten bit is used for host address and rest all net address]

now to get subnet mask we need to put 1 to all the net address and rest all 0.

so,address will be then=11111111.11111111.1111111100.00000000=255.255.252.0