This page describes how to use dynamic routing to create a Classic VPN gateway and one tunnel that uses the Border Gateway Protocol (BGP).
With dynamic routing, you do not specify local or remote traffic selectors; instead, you use a Cloud Router. Route information is exchanged dynamically.
For more information about Cloud VPN, see the following resources:
For best practices to consider before setting up Cloud VPN, see Best practices for Cloud VPN.
For more information about Cloud VPN, see the Cloud VPN overview.
For definitions of terms used on this page, see Key terms.
Requirements
General guidelines
- Review information about how dynamic routing works in Google Cloud.
- Make sure that your peer VPN gateway supports BGP.
- View sample Classic VPN topologies.
Creating Cloud Routers
When configuring a new HA VPN gateway, you can create a new Cloud Router, or you can use an existing Cloud Router with existing Cloud VPN tunnels or VLAN attachments. However, the Cloud Router that you use must not already manage a BGP session for a VLAN attachment associated with a Partner Interconnect connection because of the attachment's specific ASN requirements.
Before you begin
Set up the following items in Google Cloud to make it easier to configure Cloud VPN:
-
Sign in to your Google Account.
If you don't already have one, sign up for a new account.
-
In the Google Cloud Console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Cloud project. Learn how to confirm that billing is enabled for your project.
- Install and initialize the Cloud SDK.
-
If you are using the
gcloud
command-line tool, set your project ID with the following command. Thegcloud
instructions on this page assume that you have set your project ID before issuing commands.gcloud config set project PROJECT_ID
-
You can also view a project ID that has already been set by running the following command:
gcloud config list --format='text(core.project)'
Creating a custom VPC network and subnet
Before creating a Classic VPN gateway and tunnel, create a Virtual Private Cloud (VPC) network and at least one subnet in the region where the Classic VPN gateway resides:
- To create a custom mode VPC network (recommended), see Creating a custom mode VPC network.
- To create subnets, see Working with subnets.
Creating a gateway and tunnel
The VPN setup wizard is the only console option for creating a Classic VPN gateway. The wizard includes all required configuration steps for creating a Classic VPN gateway, tunnels, BGP sessions, and an external VPN gateway resource. However, you can complete certain steps later. For example, configuring BGP sessions.
The Create VPN gateway button only supports creating HA VPN gateways.
Console
Configure the Gateway
- Go to the VPN page in the Google Cloud Console.
Go to the VPN page- If you are creating a gateway for the first time, select the Create VPN connection button.
- Select the VPN setup wizard.
- Select the radio button for Classic VPN.
- Click Continue.
- On the Create a VPN connection page, specify the following gateway
settings:
- Name — The name of the VPN gateway. The name cannot be changed later.
- Description — Optionally, add a description.
- Network — Specify an existing VPC network in which to create the VPN gateway and tunnel.
- Region — Cloud VPN gateways and tunnels are regional objects. Choose a Google Cloud region where the gateway will be located. Instances and other resources in different regions can use the tunnel for egress traffic subject to the order of routes. For best performance, locate the gateway and tunnel in the same region as relevant Google Cloud resources.
- IP address — Create or choose an existing regional external
IP address.
Configure Tunnels
- Specify the following in the Tunnels section for the new tunnel item:
- Name — The name of the VPN tunnel. The name cannot be changed later.
- Description — Optionally, type a description.
- Remote peer IP address — Specify the external IP address of the peer VPN gateway.
- IKE version — Choose the appropriate IKE version supported by the peer VPN gateway. IKEv2 is preferred if it's supported by the peer device.
- Shared secret — Provide a pre-shared key used for authentication. The shared secret for the Cloud VPN tunnel must match the one used when you configure the counterpart tunnel on the peer VPN gateway. You can follow these directions to generate a cryptographically strong shared secret.
- Routing options — Select Dynamic (BGP).
- Cloud router — If you haven't already, create a new
Cloud Router specifying the options as noted below. Alternatively,
you can use an existing Cloud Router, if the Cloud Router
does not already manage a BGP session for an interconnect attachment
associated with a Partner Interconnect.
If you choose an existing Cloud Router, you'll still create
a new BGP session, but the Google ASN is the same. To create a new
Cloud Router, specify the following details:
- Name — The name of the Cloud Router. The name cannot be changed later.
- Description — Optionally, type a description.
- Google ASN — Choose a
private ASN
(
64512
through65534
,4200000000
through4294967294
). This Google ASN is used for all BGP sessions managed by the Cloud Router. The ASN cannot be changed later. - Click Save and continue.
- BGP session — Click the pencil icon, then specify the
following details. When you are done, click Save and continue:
- Name — The name of the BGP session. It cannot be changed later.
- Peer ASN — A public or
private
(
64512
through65534
,4200000000
through4294967294
) ASN used by your peer VPN gateway. - Advertised route priority — (Optional) The base priority Cloud Router uses when advertising the "to Google Cloud" routes. For more information, see Advertised prefixes and priorities. Your peer VPN gateway imports these as MED values.
- Cloud Router BGP IP and BGP peer IP — The two BGP
interface IP addresses must be link-local IP addresses belonging
to a common
/30
CIDR from the169.254.0.0/16
block. Each BGP IP defines the respective link-local IP used to exchange route information. For example,169.254.1.1
and169.254.1.2
belong to a common/30
block.
- If you need to create more tunnels on the same gateway, click Add tunnel and repeat the previous step. You can add more tunnels later.
- Click Create.
gcloud
In the following commands, replace:
PROJECT_ID
with the ID of your project.NETWORK
with the name of your Google Cloud network.REGION
with the Google Cloud region where you need to create the gateway and tunnel.- (Optional) The
--target-vpn-gateway-region
is the region of the Classic VPN gateway to operate on. Its value should be the same as--region
. If not specified, this option is automatically set. This option overrides the default compute/region property value for this command invocation. GW_NAME
with the name of the gateway.GW_IP_NAME
with a name for the external IP used by the gateway.
Complete the following command sequence to create a Google Cloud gateway:
Create the resources for the Cloud VPN gateway:
Create the target VPN gateway object.
gcloud compute target-vpn-gateways create GW_NAME \ --network NETWORK \ --region REGION \ --project PROJECT_ID
Reserve a regional external (static) IP address:
gcloud compute addresses create GW_IP_NAME \ --region REGION \ --project PROJECT_ID
Note the IP address (so you can use it when you configure your peer VPN gateway):
gcloud compute addresses describe GW_IP_NAME \ --region REGION \ --project PROJECT_ID \ --format='flattened(address)'
Create three forwarding rules. These rules instruct Google Cloud to send ESP (IPsec), UDP 500, and UDP 4500 traffic to the gateway.
gcloud compute forwarding-rules create fr-GW_NAME-esp \ --ip-protocol ESP \ --address GW_IP_NAME \ --target-vpn-gateway GW_NAME \ --region REGION \ --project PROJECT_ID
gcloud compute forwarding-rules create fr-GW_NAME-udp500 \ --ip-protocol UDP \ --ports 500 \ --address GW_IP_NAME \ --target-vpn-gateway GW_NAME \ --region REGION \ --project PROJECT_ID
gcloud compute forwarding-rules create fr-GW_NAME-udp4500 \ --ip-protocol UDP \ --ports 4500 \ --address GW_IP_NAME \ --target-vpn-gateway GW_NAME \ --region REGION \ --project PROJECT_ID
If you haven't already, complete the following command to create a Cloud Router. Replace the options as noted below. Alternatively, you can use an existing Cloud Router, as long as the Cloud Router does not already manage a BGP session for an interconnect attachment associated with a Partner Interconnect.
- Replace
ROUTER_NAME
with a name for the Cloud Router. - Replace
GOOGLE_ASN
with a private ASN (64512
through65534
,4200000000
through4294967294
). The Google ASN is used for all BGP sessions on the same Cloud Router, and it cannot be changed later.
gcloud compute routers create ROUTER_NAME \ --asn GOOGLE_ASN \ --network NETWORK \ --region REGION \ --project PROJECT_ID
- Replace
Create the Cloud VPN tunnel with the following details:
- Replace
TUNNEL_NAME
with a name for the tunnel. - Replace
ON_PREM_IP
with the external IP address of the peer VPN gateway. - Replace
IKE_VERS
with1
for IKEv1 or2
for IKEv2. - Replace
SHARED_SECRET
with your shared secret. The shared secret for the Cloud VPN tunnel must match the one used when you configure the counterpart tunnel on the peer VPN gateway. You can follow these directions to generate a cryptographically strong shared secret. Replace
ROUTER_NAME
with the name of the Cloud Router you want to use to manage routes for the Cloud VPN tunnel. The Cloud Router must exist before you create the tunnel.gcloud compute vpn-tunnels create TUNNEL_NAME \ --peer-address ON_PREM_IP \ --ike-version IKE_VERS \ --shared-secret SHARED_SECRET \ --router ROUTER_NAME \ --target-vpn-gateway GW_NAME \ --region REGION \ --project PROJECT_ID
- Replace
Configure a BGP session for the Cloud Router by creating an interface and BGP peer. Choose one of the following methods:
To let Google Cloud automatically choose the link-local BGP IP addresses:
Add a new interface to the Cloud Router. Supply a name for the interface by replacing
INTERFACE_NAME
.gcloud compute routers add-interface ROUTER_NAME \ --interface-name INTERFACE_NAME \ --vpn-tunnel TUNNEL_NAME \ --region REGION \ --project PROJECT_ID
Add a BGP peer to the interface. Replace
PEER_NAME
with a name for the peer, andPEER_ASN
with the ASN configured for the peer VPN gateway.gcloud compute routers add-bgp-peer ROUTER_NAME \ --peer-name PEER_NAME \ --peer-asn PEER_ASN \ --interface INTERFACE_NAME \ --region REGION \ --project PROJECT_ID
List the BGP IP addresses chosen by the Cloud Router. If you added a new interface to an existing Cloud Router, the BGP IP addresses for the new interface should be listed with the highest index number. The Peer IP Address is the BGP IP you should use to configure your peer VPN gateway.
gcloud compute routers get-status ROUTER_NAME \ --region REGION \ --project PROJECT_ID \ --format='flattened(result.bgpPeerStatus[].ipAddress, \ result.bgpPeerStatus[].peerIpAddress)'
Expected output for a Cloud Router managing a single Cloud VPN tunnel (index
0
) looks like the following, whereGOOGLE_BGP_IP
represents the BGP IP of the Cloud Router's interface andON_PREM_BGP_IP
represents the BGP IP of its peer.result.bgpPeerStatus[0].ipAddress: GOOGLE_BGP_IP result.bgpPeerStatus[0].peerIpAddress: ON_PREM_BGP_IP
To manually assign the BGP IP addresses associated with the Google Cloud BGP interface and peer:
Decide on a pair of link-local BGP IP addresses in a
/30
block from the169.254.0.0/16
range. Assign one of these BGP IP addresses to the Cloud Router in the next command by replacingGOOGLE_BGP_IP
. The other BGP IP address is used for your peer VPN gateway. You must configure your device to use that address, and replaceON_PREM_BGP_IP
in the last command, below.Add a new interface to the Cloud Router. Specify a name for the interface by replacing
INTERFACE_NAME
.gcloud compute routers add-interface ROUTER_NAME \ --interface-name INTERFACE_NAME \ --vpn-tunnel TUNNEL_NAME \ --ip-address GOOGLE_BGP_IP \ --mask-length 30 \ --region REGION \ --project PROJECT_ID
Add a BGP peer to the interface. Replace
PEER_NAME
with a name for the peer, andPEER_ASN
with the ASN configured for the peer VPN gateway.gcloud compute routers add-bgp-peer ROUTER_NAME \ --peer-name PEER_NAME \ --peer-asn PEER_ASN \ --interface INTERFACE_NAME \ --peer-ip-address ON_PREM_BGP_IP \ --region REGION \ --project PROJECT_ID
Completing the configuration
Before you can use a new Cloud VPN gateway and its associated VPN tunnel, complete the following steps:
- Set up the peer VPN gateway and configure the corresponding tunnel
there. For instructions, see the following:
- For specific configuration guidance for certain VPN devices, see Using third-party VPNs with Cloud VPN.
- For general configuration parameters, see Configuring the peer VPN gateway.
- Configure firewall rules in Google Cloud and your peer network as required.
- Check the status of your VPN tunnel and forwarding rules.
Applying an organization policy constraint that restricts peer VPN gateway IP addresses
You can create a Google Cloud organization policy constraint that defines a set of IP addresses that are allowed or denied to peer VPN gateways through Classic VPN or HA VPN tunnels. This constraint contains an allowlist or a denylist of these peer IP addresses, which goes into effect for Cloud VPN tunnels that you create after you apply the constraint. For details, see Restricting peer IP addresses through a Cloud VPN tunnel.
To create an organization policy and associate it with an organization, a folder, or a project, use the examples listed in the next sections and follow the steps in Using constraints.
Required permissions
To set a peer IP address constraint at the organization or project level, you must first be
granted the Organization Policy
Administrator role (roles/orgpolicy.policyAdmin
) for your organization.
Constraining connectivity from specific peer IP addresses
To only allow specific peer IP addresses through a Cloud VPN tunnel, perform the following steps:
- Find your organization ID by running the following command:
gcloud organizations list
The command output should look like the following example:
DISPLAY NAME ID example-organization 29252605212
-
Create a JSON file that defines your policy, as in the following example:
{ "constraint": "constraints/compute.restrictVpnPeersIPs", "listPolicy": { "allowedValues": [ "100.1.1.1", ], } }
-
Set the organization policy by using the Resource Manager
gcloud
commandset-policy
, passing in the JSON file, and using theORGANIZATION_ID
that you found in the previous step.
Constraining connectivity from any peer IP addresses
To prohibit the creation of any new Cloud VPN tunnel, follow the steps in this example constraint:
- Find your organization ID or the ID for the node in your resource hierarchy where you want to set a policy.
-
Create a JSON file like the following example:
{ "constraint": "constraints/compute.restrictVpnPeersIPs", "listPolicy": { "allValues": "DENY" } }
-
Pass in the JSON file by running the same command that you would use for restricting specific peer IP addresses.
What's next
- To find resources for maintaining VPN tunnels and gateways, see the Maintaining VPNs how-to guides.
- To use high-availability and high-throughput scenarios or multiple subnet scenarios, see Advanced configurations.
- To help you solve common issues that you might encounter when using Cloud VPN, see Troubleshooting.