How DHCP and DNS are managed in Amazon VPC

In Amazon Virtual Private Cloud (Amazon VPC), the Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) are managed through the use of DHCP options and DNS hostnames.

DHCP options are used to automatically assign IP addresses, default gateway, and DNS server information to instances within a VPC. This allows instances to communicate with each other and access the internet without requiring manual configuration.

DNS hostnames are used to assign a human-readable name to an instance's IP address. This allows instances to be accessed using a friendly name, instead of having to remember the IP address.

Here is an example of how DHCP and DNS are managed in Amazon VPC:

1. The administrator creates a VPC and configures DHCP options for the VPC. This includes specifying the IP address range for the VPC, the default gateway, and the DNS server information.
2. When an instance is launched in the VPC, it automatically receives an IP address from the DHCP options, as well as the default gateway and DNS server information.
3. The administrator can also assign a DNS hostname to the instance, using the Amazon EC2 console or the AWS CLI. This hostname is mapped to the instance's IP address, allowing the instance to be accessed using the hostname.
4. The instance can now be accessed using its hostname, rather than having to remember its IP address. This makes it easier to manage and access the instances within the VPC.

Overall, the use of DHCP options and DNS hostnames in Amazon VPC makes it easy to manage and access instances within the VPC, without requiring manual configuration of IP addresses and DNS settings.