AWS 2 Networking

Internal communication happens on L2 Layer ( MAC to MAC using a switch )
From one ip to another IP , we need a Router as the communication is happening between two networks




Check your MAC Address:





By using private IPS and NAT, the same range of ips can be used by different companies.





The world only knows about public IPS.
They are are not aware of the internal IPs, which are private
So, there is no question of conflict.

The Network will be divided into multiple Subnetworks

Classless Inter Domain Routing    based on the  Number at the END

A subnet mask hides, or "masks," the network part of a system's IP address and leaves only the host part as the machine identifier. A common subnet mask for a Class C IP address is 255.255.255.0. Each section of the subnet mask can contain a number from 0 to 256, just like an IP address.

1 What is the use of subnet mask?

It is called a subnet mask because it is used to identify network address of an IP address by perfoming a bitwise AND operation on the netmask. A Subnet mask is a 32-bit number that masks an IP address, and divides the IP address into network address and host address.

2 What is Gateway in networking?

A gateway is a hardware device that acts as a "gate" between two networks. It may be a router, firewall, server, or other device that enables traffic to flow in and out of the network. While a gateway protects the nodes within network, it also a node itself.

3 Is the Default Gateway the same as the IP address?

It is used to identify your computer. Default gateway is the address of your router/ modem. It is common for all the devices connected to same network. Your IP address is unique to your computer on your local network (but is probably not how Internet hosts see you due to address translation).

4 Is broadcast the same as Gateway?

One is the broadcast address and the other is the default gateway. ... A broadcastaddress is the one that is used by one host to communicated to another host on thesame network whereas the default gateway is this address that is used by all hosts to communicate with hosts outside the network/subnet.

The CIDR #  is  the / number
This number refers to the Network bits

10.1.0.0 /16
This refers that The first two octets belong to the Network


VPC with the subnetwork: