# Internet access

How traffic gets between your instances and the internet - Internet Gateways, route tables, NAT gateways and Floating IPs, and the two paths they form.

A VPC you create is private: nothing in it reaches the internet or can be reached from it. Internet access takes an Internet Gateway on the VPC, plus one of two ways out for each instance. A Floating IP gives one instance a public IPv4 address in both directions. A NAT gateway gives a whole subnet outbound-only access through one shared address.

The two paths from an instance to the internet:

- **Instance with a Floating IP:** the Floating IP (1:1 NAT), then the Internet Gateway, then the internet.
- **Instance without a Floating IP:** the subnet’s route table (`0.0.0.0/0`), then a NAT gateway in a public subnet, then the Internet Gateway, then the internet.

Internet traffic is IPv4 only. Instances can’t use IPv6 to or from the internet; see [VPC and subnet addressing](/docs/network/vpcs/addressing).

An instance with a Floating IP always uses it, even in a subnet routed through a NAT gateway. An instance with neither has no internet access. On both paths, the subnet’s network ACL and the instance’s security groups must also allow the traffic; see [Traffic control](/docs/network/traffic-control).

## Key concepts [#key-concepts]

| Concept | Meaning |
| --- | --- |
| Internet Gateway | Connects a whole VPC to the internet. A VPC has at most one. Attaching it adds a default route through it to the VPC’s main route table. See [Attach and detach an Internet Gateway](/docs/network/internet-access/internet-gateways). |
| Route table | Decides where a subnet’s internet-bound traffic goes: out through the Internet Gateway, through a NAT gateway, or nowhere. Every VPC has a main table, and you can add more. See [Route tables](/docs/network/internet-access/route-tables). |
| Floating IP | A public IPv4 address you hold in your project and associate with a network interface. The platform translates it 1:1 to the interface’s private address. See [Floating IPs](/docs/network/internet-access/floating-ips). |
| NAT gateway | Shared outbound IPv4 access for instances without a Floating IP. Instances behind it aren’t reachable from the internet. See [Give a private subnet internet access with a NAT gateway](/docs/network/internet-access/nat-gateways). |

## What you can do [#what-you-can-do]

- [Attach and detach an Internet Gateway](/docs/network/internet-access/internet-gateways)
- [Give a private subnet internet access with a NAT gateway](/docs/network/internet-access/nat-gateways)
- [Allocate, associate and release Floating IPs](/docs/network/internet-access/floating-ips#use-a-floating-ip)

## Limits and quotas [#limits-and-quotas]

Internet Gateways, NAT gateways and public IPv4 addresses are limited per organization and project. See [Limits](/docs/platform/reference/limits).

## Related [#related]

- [VPCs and subnets](/docs/network/vpcs)
- [Traffic control](/docs/network/traffic-control)
- [Troubleshoot Network](/docs/network/troubleshooting)