IP 2.9 IP Addresses Introduction

#1

I could not understand the CIDR pattern for IP address identification. Arnav Bhaiyya talked about 121.11.34.0/48 example. He said first 48 bits are fixed and in 121.11.34.0/256, first 256 bits are fixed. In the last one, i.e. “/8” example, he said the first 8 DIGITS are fixed. I got confused between bits-digits-decimal values. He said IPv4 has 32 bits, then how can we fix 48 or 256 bits? Arnav Bhaiyya, can you please take one small session/post on CIDR?

#2

Hi Priyam

/256 was an example. Actually nothing larger than /32 can exist.

121.23.33.44/32 means only 121.23.33.44 itself

121.23.33.44/31 means 121.23.33.44 and 121.23.33.45 both

Hope you got the hang of it ?

#3

Yeah… I also thought the same but just wanted to be sure. Thank you ! :slight_smile:

#4

Sir but if we use IPv6 than it can be extended till 128 bits,right?
and then we can use /x and 0<x<=128

#5

Hi @championswimmer-t
121.23.33.44/31 means just last bit is not fixed so if we flip it we have only these two addresses 121.23.33.44 and 121.23.33.45. How it can be 25?, may be I didn’t get it correctly.
thanks.

#7

Probably it was a typo. Fixed it.