Configure Private Google Access

This page describes how to enable and configure Private Google Access. By default, when a Compute Engine VM lacks an external IP address assigned to its network interface, it can only send packets to other internal IP address destinations. You can allow these VMs to connect to the set of external IP addresses used by Google APIs and services by enabling Private Google Access on the subnet used by the VM's network interface.

Private Google Access also allows access to the external IP addresses used by App Engine, including third-party App Engine-based services.

To view the eligible APIs and services that you can use with Private Google Access, see supported services in the Private Google Access overview.

See Private Access Options for Services for background information about Private Google Access and other private connectivity options offered by Google Cloud.

Specifications

A VM interface can send packets to the external IP addresses of Google APIs and services using Private Google Access if all these conditions are met:

• The VM interface is connected to a subnet where Private Google Access is enabled.

• The VPC network that contains the subnet meets the network requirements for Google APIs and services.

• The VM interface does not have an external IP address assigned.

• The source IP address of packets sent from the VM matches one of the following IP addresses.

  • The VM interface's primary internal IPv4 address
  • The VM interface's internal IPv6 address
  • An internal IPv4 address from an alias IP range

A VM with an external IPv4 or IPv6 address assigned to its network interface doesn't need Private Google Access to connect to Google APIs and services. However, the VPC network must meet the requirements for accessing Google APIs and services.

Network requirements

Private Google Access has the following requirements:

• Because Private Google Access is enabled on a per-subnet basis, you must use a VPC network. Legacy networks are not supported because they don't support subnets.

• You must enable the Google APIs you need to use in the Google Cloud console, on the APIs & services page.

• If you want to connect to Google APIs and services using IPv6, you must meet both of these requirements:

  • Your VM must be configured with a /96 IPv6 address range.

  • The software running on the VM must send packets whose sources match one of those IPv6 addresses from that range.

• Depending on your chosen configuration, you might need to update DNS entries, routes, and firewall rules. For more information, see Summary of configuration options.

Permissions

Project owners, editors, and IAM principals with the Network Admin role can create or update subnets and assign IP addresses.

For more information on roles, read the IAM roles documentation.

Logging

Cloud Logging captures all API requests made from VM instances in subnets that have Private Google Access enabled. Log entries identify the source of the API request as an internal IP address of the calling instance.

You can configure daily usage and monthly rollup reports to be delivered to a Cloud Storage bucket. See the Viewing Usage Reports page for details.

Summary of configuration options

The following table summarizes the different ways that you can configure Private Google Access. For more detailed configuration information, see Network configuration.

Network configuration

This section describes the basic network requirements you must meet in order for a VM in your VPC network to access Google APIs and services.

Domain options

Choose the domain that you want to use to access Google APIs and services.

The private.googleapis.com and restricted.googleapis.com virtual IP addresses (VIPs) support only HTTP-based protocols over TCP (HTTP, HTTPS, and HTTP/2). All other protocols, including MQTT and ICMP, are not supported.

IPv6 support for private.googleapis.com and restricted.googleapis.com

The following IPv6 address ranges can be used to direct traffic from IPv6 clients to Google APIs and services:

• private.googleapis.com: 2600:2d00:0002:2000::/64
• restricted.googleapis.com: 2600:2d00:0002:1000::/64

Consider configuring the IPv6 addresses if you want to use the private.googleapis.com or restricted.googleapis.com domain, and you have clients that use IPv6 addresses. IPv6 clients that also have IPv4 addresses configured can reach Google APIs and services by using the IPv4 addresses. Not all services accept traffic from IPv6 clients.

DNS configuration

For connectivity to Google APIs and services, you can choose to send packets to the IP addresses associated with the private.googleapis.com or restricted.googleapis.com VIP. To use a VIP, you must configure DNS so that VMs in your VPC network reach services by using the VIP addresses instead of the public IP addresses.

The following sections describe how to use DNS zones to send packets to the IP addresses that are associated with your chosen VIP. Follow the instructions for all scenarios that apply to you:

• If you use services that have *.googleapis.com domain names, see Configure DNS for googleapis.com.

• If you use services that have other domain names, see Configure DNS for other domains.

  For example, if you use Google Kubernetes Engine (GKE), you also need to configure *.gcr.io and *.pkg.dev, or if you use Cloud Run, you need to configure *.run.app.

• If you use Cloud Storage buckets, and you send requests to a Cloud Storage custom domain name, see Configure DNS for Cloud Storage custom domain names.

When you configure DNS records for the VIPs, use only the IP addresses that are described in the following steps. Do not mix addresses from the private.googleapis.com and restricted.googleapis.com VIPs. This can cause intermittent failures because the services that are offered differ based on a packet's destination.

Configure DNS for googleapis.com

Create a DNS zone and records for googleapis.com:

1. Create a private DNS zone for googleapis.com. Consider creating a Cloud DNS private zone for this purpose.

2. In the googleapis.com zone, create the following private DNS records for either private.googleapis.com or restricted.googleapis.com, depending on which domain you've chosen to use.

   • For private.googleapis.com:

     1. Create an A record for private.googleapis.com pointing to the following IP addresses: 199.36.153.8, 199.36.153.9, 199.36.153.10, 199.36.153.11.

     2. To connect to APIs using IPv6 addresses, also configure an AAAA record for private.googleapis.com pointing to 2600:2d00:0002:2000::.

   • For restricted.googleapis.com:

     1. Create an A record for restricted.googleapis.com pointing to the following IP addresses: 199.36.153.4, 199.36.153.5, 199.36.153.6, 199.36.153.7.

     2. To connect to APIs using IPv6 addresses, also create an AAAA record for restricted.googleapis.com pointing to 2600:2d00:0002:1000::.

   To create private DNS records in Cloud DNS, see add a record.

3. In the googleapis.com zone, create a CNAME record for *.googleapis.com that points to the domain that you've configured: private.googleapis.com or restricted.googleapis.com.

Configure DNS for other domains

Some Google APIs and services are provided using additional domain names, including *.gcr.io, *.gstatic.com, *.pkg.dev, pki.goog, and *.run.app. Refer to the domain and IP address ranges table in Domain options to determine if the additional domain's services can be accessed using private.googleapis.com or restricted.googleapis.com. Then, for each of the additional domains:

1. Create a DNS zone for DOMAIN (for example, gcr.io). If you're using Cloud DNS, make sure this zone is located in the same project as your googleapis.com private zone.

2. In this DNS zone, create the following private DNS records for either private.googleapis.com or restricted.googleapis.com, depending on which domain you've chosen to use.

   • For private.googleapis.com:

     1. Create an A record for DOMAIN pointing to the following IP addresses: 199.36.153.8, 199.36.153.9, 199.36.153.10, 199.36.153.11.

     2. To connect to APIs using IPv6 addresses, also create an AAAA record for DOMAIN pointing to 2600:2d00:0002:2000::.

   • For restricted.googleapis.com:

     1. Create an A record for DOMAIN pointing to the following IP addresses: 199.36.153.4, 199.36.153.5, 199.36.153.6, 199.36.153.7.

     2. To connect to APIs using IPv6 addresses, also create an AAAA record for restricted.googleapis.com pointing to 2600:2d00:0002:1000::.

3. In the DOMAIN zone, create a CNAME record for *.DOMAIN that points to DOMAIN. For example, create a CNAME record for *.gcr.io that points to gcr.io.

Configure DNS for Cloud Storage custom domain names

If you are using Cloud Storage buckets, and you send requests to a Cloud Storage custom domain name, configuring DNS records for the custom Cloud Storage domain name to point to the IP addresses for private.googleapis.com or restricted.googleapis.com is not sufficient to allow access to the Cloud Storage buckets.

If you want to send requests to a Cloud Storage custom domain name, you must also explicitly set the HTTP request's Host header and TLS SNI to storage.googleapis.com The IP addresses for private.googleapis.com and restricted.googleapis.com do not support custom Cloud Storage hostnames in HTTP request Host headers and TLS SNIs.

Routing options

Your VPC network must have appropriate routes whose next hops are the default internet gateway. Google Cloud does not support routing traffic to Google APIs and services through other VM instances or custom next hops. Despite being called default internet gateway, packets sent from VMs in your VPC network to Google APIs and services remain within Google's network.

• If you select the default domains, your VM instances connect to Google APIs and services using a subset of Google's external IP addresses. These IP addresses are publicly routable, but the path from a VM in a VPC network to those addresses remains within Google's network.

• Google doesn't publish routes on the internet to any of the IP addresses used by either the private.googleapis.com or restricted.googleapis.com domains. Consequently, these domains can only be accessed by VMs in a VPC network or on-premises systems connected to a VPC network.

If your VPC network contains a default route whose next hop is the default internet gateway, you can use that route to access Google APIs and services, without needing to create custom routes. See routing with a default route for details.

If you have replaced a default route (destination 0.0.0.0/0 or ::0/0) with a custom route whose next hop is not the default internet gateway, you can meet the routing requirements for Google APIs and services using custom routing instead.

If your VPC network does not have an IPv6 default route, you won't have IPv6 connectivity to Google APIs and services. Add an IPv6 default route to allow IPv6 connectivity.

Routing with a default route

Each VPC network contains an IPv4 default route (0.0.0.0/0) when it is created. If you enable external IPv6 addresses on a subnet, a system-generated IPv6 default route (::/0) is added to that VPC network.

The default routes provides a path to the IP addresses for the following destinations:

• The default domains.

• private.googleapis.com: 199.36.153.8/30 and 2600:2d00:0002:2000::/64.

• restricted.googleapis.com: 199.36.153.4/30 and 2600:2d00:0002:1000::/64.

To check the configuration of a default route in a given network, follow these directions.

gcloud compute routes list \
    --filter="default-internet-gateway NETWORK_NAME"

If you need to create a replacement default IPv4 route, see Adding a static route.

If you need to create a replacement default IPv6 route, see Adding an IPv6 default route.

Custom routing

As an alternative to a default route, you can use custom static routes, each having a more specific destination, and each using the default internet gateway next hop. The number of routes you need and their destination IP addresses depend on the domain that you choose.

• Default domains: you must have routes for the IP address ranges for Google APIs and services.
• private.googleapis.com: 199.36.153.8/30 and 2600:2d00:0002:2000::/64
• restricted.googleapis.com: 199.36.153.4/30 and 2600:2d00:0002:1000::/64

Additionally, we recommend that you add routes for 34.126.0.0/18 and 2001:4860:8040::/42. For more information, see Summary of configuration options.

To check the configuration of custom routes for Google APIs and services in a given network, follow these directions.

gcloud compute routes list \
    --filter="default-internet-gateway NETWORK_NAME"

If you need to create routes, see Adding a static route.

Firewall configuration

The firewall configuration of your VPC network must allow access from VMs to the IP addresses used by Google APIs and services. The implied allow egress rule satisfies this requirement.

In some firewall configurations, you need to create specific egress allow rules. For example, suppose you've created an egress deny rule that blocks traffic to all destinations (0.0.0.0 for IPv4 or ::/0 for IPv6). In that case, you must create one egress allow firewall rule whose priority is higher than the egress deny rule for each IP address range used by your chosen domain for Google APIs and services.

• Default domains: all IP address ranges for Google APIs and services.
• private.googleapis.com: 199.36.153.8/30 and 2600:2d00:0002:2000::/64
• restricted.googleapis.com: 199.36.153.4/30 and 2600:2d00:0002:1000::/64

Additionally, we recommend that you include 34.126.0.0/18 and 2001:4860:8040::/42 in your egress allow firewall rule. For more information, see Summary of configuration options.

To create firewall rules, see Creating firewall rules. You can limit the VMs to which the firewall rules apply when you define the target of each egress allow rule.

IP addresses for default domains

This section describes how to create a list of default domain IP ranges used by Google APIs and services. These ranges are allocated dynamically and change often, so it's not possible to define specific IP ranges for individual services or APIs. To maintain an accurate list, set up automation to run the script every day. For alternatives to maintaining a list of IP address ranges, consider using the private.googleapis.com VIP or Private Service Connect.

Follow these steps to determine the IP address ranges used by the default domains, such as *.googleapis.com and *.gcr.io.

• Google publishes the complete list of IP ranges that it makes available to users on the internet in goog.json.

• Google also publishes a list of global and regional external IP addresses ranges available for customers' Google Cloud resources in cloud.json.

The IP addresses used by the default domains for Google APIs and services fit within the list of ranges computed by taking away all ranges in cloud.json from those in goog.json. These lists are updated frequently.

You can use the following Python script to create a list of IP address ranges that include those used by the default domains for Google APIs and services.

For information about running this script, see How to run.

from __future__ import print_function

import json

try:
    from urllib import urlopen
except ImportError:
    from urllib.request import urlopen
    from urllib.error import HTTPError

import netaddr

IPRANGE_URLS = {
    "goog": "https://www.gstatic.com/ipranges/goog.json",
    "cloud": "https://www.gstatic.com/ipranges/cloud.json",
}


def read_url(url):
    try:
        return json.loads(urlopen(url).read())
    except (IOError, HTTPError):
        print("ERROR: Invalid HTTP response from %s" % url)
    except json.decoder.JSONDecodeError:
        print("ERROR: Could not parse HTTP response from %s" % url)


def get_data(link):
    data = read_url(link)
    if data:
        print("{} published: {}".format(link, data.get("creationTime")))
        cidrs = netaddr.IPSet()
        for e in data["prefixes"]:
            if "ipv4Prefix" in e:
                cidrs.add(e.get("ipv4Prefix"))
            if "ipv6Prefix" in e:
                cidrs.add(e.get("ipv6Prefix"))
        return cidrs


def main():
    cidrs = {group: get_data(link) for group, link in IPRANGE_URLS.items()}
    if len(cidrs) != 2:
        raise ValueError("ERROR: Could process data from Google")
    print("IP ranges for Google APIs and services default domains:")
    for ip in (cidrs["goog"] - cidrs["cloud"]).iter_cidrs():
        print(ip)


if __name__ == "__main__":
    main()

Private Google Access configuration

You can enable Private Google Access after you've met the network requirements in your VPC network.

Enable Private Google Access

Follow these steps to enable Private Google Access:

gcloud compute networks subnets create SUBNET_NAME \
    --region=REGION \
    --network=NETWORK_NAME \
    --range=PRIMARY_IP_RANGE \
    [ --stack-type=STACK_TYPE ] \
    [ --ipv6-access-type=IPv6_ACCESS_TYPE ] \
    --enable-private-ip-google-access

Disable Private Google Access

Follow these steps to disable Private Google Access for an existing subnet:

What's next

• Configure Private Google Access for on-premises hosts