NAT Gateway
A managed service that enables instances in a private subnet to initiate outbound traffic to the internet while preventing unsolicited inbound traffic.
Description
A NAT Gateway (Network Address Translation Gateway) is a highly available, managed service provided by Amazon Web Services (AWS) that allows instances within a private subnet to connect to the internet for purposes like software updates, API calls, or accessing external services. It acts as an intermediary between the private subnet and the internet, translating the private IP addresses of the instances to a public IP address assigned to the NAT Gateway. This ensures that while the instances can initiate outbound connections, they are not directly exposed to incoming traffic from the internet, thereby enhancing security. NAT Gateways are designed to scale automatically with the traffic demands, providing a cost-effective solution for internet access without the need to manage the underlying infrastructure. They are also easier to configure and maintain compared to NAT instances, which require manual setup and management. AWS offers a simple interface to set up NAT Gateways, making it a preferred choice for many organizations looking to secure their cloud environments.
Examples
- A web application hosted in an AWS VPC that needs to update its software dependencies can use a NAT Gateway to reach external repositories without exposing its instances to the internet.
- An analytics application running on EC2 instances in a private subnet may require access to third-party APIs; a NAT Gateway allows it to send requests while keeping its resources secure.
Additional Information
- NAT Gateways support both IPv4 and IPv6 traffic, but the public IP address can only handle IPv4.
- They incur costs based on the amount of data processed and the hours they are provisioned, making it important to monitor usage for cost optimization.