<ul>
<li>AWS reserves 5 IP addresses (first 4 and last 1) in each subnet</li>
<li>These 5 IP addresses are not available for use and can't be assigned to an EC2 instance</li>
<li>e.g: If CIDR block 10.0.0.0/24, reserved IP address are<ul>
<li>10.0.0.0 - Network Address</li>
<li>10.0.0.1 - reserved by AWS for the VPC router</li>
<li>10.0.0.2 - reserved by AWS for mapping to Amazon-provided DNS</li>
<li>10.0.0.3 - reserved by AWS for future use</li>
<li>10.0.0.255 - Network Broadcast Address. AWS does not support broadcast in a VPC, therefore the address is reserved</li>
</ul>
</li>
</ul>


- AWS reserves 5 IP addresses (first 4 and last 1) in each subnet
- These 5 IP addresses are not available for use and can't be assigned to an EC2 instance
- e.g: If CIDR block 10.0.0.0/24, reserved IP address are
  - 10.0.0.0 - Network Address
  - 10.0.0.1 - reserved by AWS for the VPC router
  - 10.0.0.2 - reserved by AWS for mapping to Amazon-provided DNS
  - 10.0.0.3 - reserved by AWS for future use
  - 10.0.0.255 - Network Broadcast Address. AWS does not support broadcast in a VPC, therefore the address is reserved


VPC - Subnet - IPv4