Private Google Access for on-premises hosts
On-premises hosts can reach Google APIs and services by using Cloud VPN or Cloud Interconnect from your on-premises network to Google Cloud. On-premises hosts can send traffic from the following types of source IP addresses:
- a private IP address, such as an RFC 1918 address
- a privately used public IP address, except for a Google-owned public IP address. (Private Google Access for on-premises hosts does not support re-using Google public IP addresses as sources in your on-premises network.)
To enable Private Google Access for on-premises hosts, you must configure DNS, firewall rules, and routes in your on-premises and VPC networks. You don't need to enable Private Google Access for any subnets in your VPC network as you would for Private Google Access for Google Cloud VM instances.
On-premises hosts must connect to Google APIs and services by using the virtual
IP addresses (VIPs) for either the restricted.googleapis.com or
private.googleapis.com domains. Refer to Private Google Access-specific
domains and VIPs for more details.
Google publicly publishes DNS A records that resolve the domains to a VIP range. Even though the ranges have external IP addresses, Google does not publish routes for them. Therefore, you must add a custom route advertisement on a Cloud Router and have an appropriate custom static route in your VPC network for the VIP's destination.
The route must have a destination matching one of the VIP ranges and a next hop being the default internet gateway. Traffic sent to the VIP range stays within Google's network instead of traversing the public internet because Google does not publish routes to them externally.
For configuration information, see Configuring Private Google Access for on-premises hosts.
Private Google Access-specific domains and VIPs
The following table describes the domain names and their VIP range. You must use one of these VIPs for Private Google Access for on-premises hosts.
The private.googleapis.com and restricted.googleapis.com VIPs support
only HTTP-based protocols over TCP (HTTP, HTTPS, and HTTP/2). All other protocols, including MQTT
and ICMP are not supported.
| Domain and IP address ranges | Supported services | Example usage |
|---|---|---|
| Default domains All domain names for Google APIs and services except for private.googleapis.com and restricted.googleapis.com.Various IP address ranges—you can determine a set of IP ranges that contains the possible addresses used by the default domains by referencing IP addresses for default domains |
Enables API access to most Google APIs and services regardless of whether they are supported by VPC Service Controls. Includes API access to Google Maps, Google Ads, Google Cloud. Includes Google Workspace and other web applications. | The default domains are used when you don't configure DNS records for
private.googleapis.com and
restricted.googleapis.com |
private.googleapis.com199.36.153.8/30 |
Enables API access to most Google APIs and services regardless of
whether they are supported by VPC Service Controls. Includes API access to
Maps, Google Ads, Google Cloud, and most other
Google APIs, including the lists below. Does not support Google Workspace web
applications. Does not support any interactive websites. Domain names that match:
|
Use Choose
|
restricted.googleapis.com199.36.153.4/30 |
Enables API access to
Google APIs and
services that are supported by VPC Service Controls. Blocks access to Google APIs and services that do not support VPC Service Controls. Does not support Google Workspace web applications or Google Workspace APIs. |
Use Choose |
Supported services
Services available to on-premises hosts are limited to those supported by the domain name and VIP used to access them. Refer to Private Google Access-specific domains and VIPs for details.
Example
In the following example, the on-premises network is connected to a
VPC network through a Cloud VPN tunnel. Traffic from
on-premises hosts to Google APIs travels through the tunnel to the
VPC network. After traffic reaches the VPC
network, it is sent through a route that uses the default internet gateway as
its next hop. This next hop allows traffic to leave the VPC
network and be delivered to restricted.googleapis.com (199.36.153.4/30).
- The on-premises DNS configuration maps
*.googleapis.comrequests torestricted.googleapis.com, which resolves to the199.36.153.4/30. - Cloud Router has been configured to advertise the
199.36.153.4/30IP address range through the Cloud VPN tunnel by using a custom route advertisement. Traffic going to Google APIs is routed through the tunnel to the VPC network. - A custom static route was added to the VPC network that
directs traffic with the destination
199.36.153.4/30to the default internet gateway (as the next hop). Google then routes traffic to the appropriate API or service. - If you created a Cloud DNS managed private zone for
*.googleapis.comthat maps to199.36.153.4/30and have authorized that zone for use by your VPC network, requests to anything in thegoogleapis.comdomain are sent to the IP addresses that are used byrestricted.googleapis.com. Only the supported APIs are accessible with this configuration, which might cause other services to be unreachable. Cloud DNS doesn't support partial overrides. If you require partial overrides, use BIND.
What's next
- To configure Private Google Access for on-premises hosts, Configuring Private Google Access for on-premises hosts.