Types of VPC in AWS

There are two types of VPC:

1. Default VPC.

2. Custom VPC.

Default VPC:-

• Created in each AWS region when an AWS account is created.

• Has default CIDR, Security group, NACL and Route table settings.

• Has an internet gateway by default.

Custom VPC:-

• Custom vpc is created by AWS account owner.

• Aws user creating the custom vpc decides the CIDR.

• Has its own default security group, NACL and route table.

• Does not have an internet gateway by default, One needs to be created if needed.

Types of subnets:

1. Public subnet.

2. Private subnet.

Public Subnet:

• If a subnet's traffic is routed to an internet gateway, that subnet is known as a public subnet.

• If you want your instance in a public subnet to communicate with the internet over IPV4, it must have a public IP address or Elastic IP address.

Private Subnet:

• If a subnet does not have a route to the internet gateway, that subnet is known as a Private subnet.

Note:

• When you create a VPC, you must specify an IPV4 CIDR Block for the vpc.

• The allowed CIDR block range is between 0.0.0.0/16 to 0.0.0.0/28 netmask.

• The first four and last IP address cannot be assigned.

For example:

1. 10.0.0.0 --> Network address.

2. 10.0.0.1 --> Reserved by AWS for VPC Router.

3. 10.0.0.2 --> Reserved by AWS for the IP address of DNS.

4. 10.0.0.3 --> Reserved for future use.

5. And the last one as we all know, is the broadcast address of any IP address. which is 10.0.0.255 --> Broadcast Address.