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?
    • Google.com 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 192.168.0.198 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.
ip: 192.168.0.198
sm: 255.255.255.0
------------------
    192.168.0 (255) => Network Id
    198(0) => Host id


ip : 10.10.10.18
sm : 255.255.0.0
-----------------
    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

Google.com 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 google.com 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

Exercise:

  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