AWS Classroom Series – 27/Oct/2020

What is ip address, subnet mask and default gateway

  • To uniquely identify a system in a network every system is given an unique address which is referred as IP address
  • Execute ipconfig (ifconfig) from terminal Preview
  • From the above image we can understand ip address which is unique id given to the system in a network for communication Preview
  • Basic Network Rules
    • A system (laptop/mobile) can communicate with any other system (laptop/mobile) in the same network
  • Two Questions to be answered
    • How does system know that other system is from same network?
    • is not in my home network then how is it working?

How does system know that other system is from same network?

  • IP Address: Ip address is combination of network id and host id
  • The ipaddress in the above example was What is network id in this & What is host id in this?
  • Just by looking at ip we will not be able to tell network id and host id, we need subnet mask for that
  • Lets try the below sample.
    192.168.0 (255) => Network Id
    198(0) => Host id

ip :
sm :
    10.10 (255) => Network Id
    10.18 (0)   => Host id
  • System will come to know if the other system is in same network if it has same network id
  • Little bit more ip:
    • The ip we have used is reffered as IPv4 which is a 32 bit number. Ip’s are represented as x.x.x.x where x => 8 bit number. x has minimum value of 0 and maximum value of 255 is not in my home network then how is it working?

  • Lets ping google Preview
  • In networking based on rule two systems can communicate only if they are in same network.
  • There is a networking component called as router. The responsibility of router is to forward packets from one network to other. Preview
  • Generally router ip address is stored as Default Gateway Preview
  • Your router forwards the packet to other network which forwards to other this happens till is reached (hopping).

What are components of my home internet connection & its relavance

  • Router: Router is used forward packets to the internet
  • Modem: connects to the internet service providers network
  • What happens if modem is down?
    • Will we have network? Yes we will have network without internet access Preview
  • What will happen if router is down?
    • We will have no network (Network will be down) Preview


  1. Create AWS Account Refer Here
  2. Create one ec2 instance and delete it Refer Here
  3. Install necessary Softwares Refer Here

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

About learningthoughtsadmin