Internet Gateway
Internet Gateway is a crucial VPC component that allows communication between your VPC and the Internet. You can connect to the Internet by adding a route toward the internet gateway to the route table associated with the subnet and connecting a public IP to a resource (e.g. BCS instance) on the subnet. Likewise, resources on the Internet can access resources on the subnet using public IP.
Internet gateway fundamentals
- To communicate with the internet, an instance within a subnet needs to be associated with a public IP.
- It's essential to configure security group policies to allow the intended internet traffic to and from instances.
- Internet gateways are exclusive to public subnets.
Internet gateway by subnet type
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Private subnet: Represents a subnet with no route to the internet gateway in the associated route table. Even if resources in a private subnet have public IPs attached, without an internet gateway, they cannot communicate with the Internet. One method to enable Internet access from private subnets is by using NAT instances.
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Public subnet: Represents a subnet with a route to the internet gateway in the associated route table. Resources in a public subnet can access the Internet through this route.
Enabling internet access
The following describes how to support Internet access using the internet gateway:
- Refer to Create VPC to create a public subnet. When creating a public subnet, it automatically generates a route table with an internet gateway route association.
- Create instances in the public subnet. Refer to Create and connect instance for more details.
- Attach public IPs to the created instances.
- Connect to the instances using SSH or remote desktop.
- For Linux instances, refer to Connect to Linux instance.
- For Windows instances, refer to Connect to Windows instance.
Disabling internet access
The following describes how to disable Internet access from resources using the internet gateway:
- Disassociate any public IPs from resources linked to the subnets connected to the internet gateway.
- Remove the internet gateway route from the route table associated with the public subnet.