VPC(Virtual Private Cloud)

A VPC is a virtual network dedicated to your AWS account. It is logically isolated from other virtual networks.

Types of VPC

1. Default VPC

   • It is created by AWS when the account is created
   • All the advanced features are provided.

2. Custom VPC
   It is created explicitly with the required features like subnet, NAT, security groups, Internet gateway, route tables, etc.

IP address

• It is a logical numerical label assigned as a unique entity to each device in a network.
• It is used to locate the host in the network through the Network ID and Host ID present in the IP address.

IP address had 4 bytes and each byte has 8bit i.e 32 bits(IPv4)

The drawback of IPv4 is limited address space to overcome that we have Ipv6.
The internet is undergoing a gradual transition to IPv6.

There are 3 types of IP address
1. Public IP
2. Private IP
3. Elastic IP
Details of Types of IP Address

CIDR(Classless Inter-Domain Routing)

• It helps to reduce the wastage of Ip addresses.
• It also helps to determine how larger is the network.

Components of VPC

1. Internet Gateway(IGT):

   • This is used to connect over the Internet.
   • IGT helps to communicate over the internet using the target in the routing table

2. NAT Gateways:

   • These are Network Address Translation gateway that helps to connect the private subnet to the internet through a public IP but the internet cannot access the private subnet.
   • NAT gateway is created in the pubic subnet and it connects to private through route table.
   • Each NAT gateway is created in a specific Availability Zone and implemented with redundancy in that zone.

   

3. Route Table: It defines how the traffic is routed between each subnet.
   

4. Subnets: These are subnetworks. It is a logical sub-division of a large network.

There are two types of subnets:

1. Private Subnet:
   • Resources are not exposed to the outer world.
   • These use only the private IPs.
   • These are mainly used for backend purposes like database storage.
2. Public Subnet:
   • Resources are exposed to the internet through the Internet gateway.
   • It uses both public and private IP.