Your VPC

• A virtual private cloud is a virtual network that closely resembles a traditional networking that you operate in your own data center with the benefits of using the scalable infrastructure of AWS
• It is logically isolated from other virtual network in the AWS cloud.
• Maximum five VPC can be created and 200 subnet in one VPC can be created.
• we can allocate maximum five Elastic IP address to our VPC.
• Once we created VPC - DHCP, Network ACL and Security Group will be automatically created.
• A vpc is confined to an AWS region and doesn't extend between regions
• Allow us use multiple layer of security by using ACL, IGW, Security Groups, VPN, etc.

Architectures

Components of VPC

Some of the components of the VPC are -

• Implied router and routing table
• Security Group
• Network ACL
• Virtual private gateway
• Peering connection
• Elastic IP

Types of VPC

There are two types of VPC -

Default VPC

• Created in each AWS region when an AWS account is created.
• Has default - CIDR, Security Group, Network ACL and Route Table settings.
• Has an Internet gateway by default.

Custom VPC

• Created by AWS account user.

• AWS User decide the CIDR and subnet.

• Has its own Security Group, Network ACL and Routing Table.

• Doesn't have an Internet gateway by default, one needs to be created if needed.

• When you create vpc you must -

  1. Create VPC
  2. Creates Subnets
  3. Create Internet gateway
  4. Defined routing Table

  (must be in sequence)

Points to remember

• Once the VPC is created you can't change its CIDR block range.
• If you need different CIDR create a new VPC.
• The different VPC within a subnet can not overlap.
• You can however expand your VPC CIDR by adding new or extra IP address ranges (accept government cloud and AWS China).