A networking component that enables resources in a virtual network to communicate with the internet. Available as AWS Internet Gateway, Azure Internet routing, and implicit in GCP VPC networks. Like the main entrance of a building connecting inside to outside.
Web servers in a public subnet use an Internet Gateway to serve websites to users on the internet while databases in private subnets remain isolated.
AWS and OCI use an explicit Internet Gateway resource attached to a VPC/VCN to enable direct internet connectivity for public subnets (with proper routes and public IPs). Azure does not have a single 'Internet Gateway' resource; outbound/inbound internet access is provided through system routes, public IPs, and services like NAT Gateway, Load Balancer, and Application Gateway depending on the scenario. In GCP, VPCs have built-in internet connectivity; internet access is controlled via routes, external IPs, Cloud NAT (egress without external IPs), and firewall rules rather than an attachable IGW object.
Explore real-world architectures from our community that use Internet Gateway: