Configure HA VPN over Cloud Interconnect

This document provides the steps required to deploy HA VPN on top of the encrypted VLAN attachments of your Cloud Interconnect connection. These steps apply to HA VPN for both Dedicated Interconnect and Partner Interconnect.

When you create an HA VPN gateway for an HA VPN over Cloud Interconnect deployment, you associate that HA VPN gateway with your two encrypted VLAN attachments. You associate each VLAN attachment with an HA VPN gateway interface. The first VLAN attachment in the first edge availability domain, zone1, corresponds to HA VPN interface 0. The second VLAN attachment in zone2 corresponds to HA VPN interface 1.

After you create your encrypted VLAN attachments and HA VPN gateways, you can create the HA VPN tunnels to the peer VPN gateways. Each HA VPN tunnel has a bandwidth of 3 Gbps. Therefore, to match the capacity of your VLAN attachment, you must create multiple HA VPN tunnels.

VLAN capacity and recommended number of tunnels

The section provides an estimate of the number of tunnels that you might need based on the capacity of your VLAN attachment. VLAN attachment capacity covers both egress and ingress traffic, and the number of tunnels in the table might not reflect your network's particular traffic patterns.

Use the following table as a starting point and monitor traffic utilization of your HA VPN tunnels. To ensure adequate capacity for failover in your tunnels, we recommend that you do not exceed 50% of either the 3-Gbps bandwidth limit or the 250,000-pps packet rate limit for a given VPN tunnel.

For more information about setting up monitoring and alerts for Cloud VPN tunnels, see View logs and metrics.

VLAN attachment capacity Number of tunnels for each VLAN attachment Total number of tunnels for entire deployment
2 Gbps or fewer 1 2
5 Gbps 2 4
10 Gbps 4 8
20 Gbps 7 14
50 Gbps 17 34

Gateway and tunnel mapping

You do not need to have a one-to-one mapping of peer VPN gateways to HA VPN gateways. You can add multiple tunnels to each interface of the HA VPN gateway as long as there are interfaces on the peer VPN gateway that have not yet been mapped to that particular HA VPN gateway interface. There can only be one unique mapping or tunnel between a specific HA VPN gateway interface and a specific peer VPN gateway interface.

Thus, you can have the following configurations:

  • Multiple HA VPN gateways that tunnel to a single peer VPN gateway (with multiple interfaces)
  • A single HA VPN gateway that tunnels to multiple peer VPN gateways
  • Multiple HA VPN gateways that tunnel to multiple peer VPN gateways

As a general rule, the number of HA VPN gateways that you need to deploy is determined by how many peer VPN gateways with unused interfaces you have available in your on-premises network.

The following diagrams provide examples of tunnel mappings between HA VPN and peer VPN gateways.

Example 1: One HA VPN to two peer VPN

Example of one HA VPN gateway to two peer VPN gateways (click to enlarge).
Figure 1: Example of one HA VPN gateway to two peer VPN gateways (click to enlarge).

Example 2: Two HA VPN to one peer VPN

Example of two HA VPN gateways to one peer VPN gateway (click to enlarge).
Figure 2: Example of two HA VPN gateways to one peer VPN gateway (click to enlarge).

Create HA VPN gateways

Console

This procedure assumes that you have already created and configured your encrypted VLAN attachments by using the Google Cloud console:

To create an HA VPN gateway, follow these steps:

  1. In the Google Cloud console, continue to the next section of the HA VPN over Cloud Interconnect deployment wizard.

    After you complete the Cloud Router for Cloud Interconnect configuration, the Create VPN gateways page appears.

    The HA VPN over Cloud Interconnect configuration wizard automatically creates HA VPN gateways based on the capacity that you configured for your VLAN attachments. For example, if you specified 5 Gbps as the capacity of each VLAN attachment, the wizard creates two HA VPN gateways.

  2. Optional: Click Expand to change the generated name of each HA VPN gateway.

  3. Optional: If you want to add more HA VPN gateways, click Add another gateway. Specify a Name and an optional Description. Then, click Done.

  4. Click Create and Continue.

gcloud

  1. Use the VLAN capacity and tunnels table to estimate how many VPN tunnels are needed to match the capacity of your VLAN attachment. You need to create at least one HA VPN gateway to be able to create these HA VPN tunnels.

    In the following example, a 5-Gbps capacity VLAN attachment might require four tunnels.

  2. Create the HA VPN gateways.

    For example, the following command creates two HA VPN gateways and assigns the gateway interfaces to your encrypted VLAN attachments.

    gcloud compute vpn-gateways create vpn-gateway-a \
  --network network-a \
  --region us-central1 \
  --interconnect-attachments \
    attachment-a-zone1,attachment-a-zone2

    gcloud compute vpn-gateways create vpn-gateway-b \
  --network network-a \
  --region us-central1 \
  --interconnect-attachments \
    attachment-a-zone1,attachment-a-zone2

For the --interconnect-attachments parameter, you list both VLAN attachments. The first VLAN attachment that you list is assigned to interface 0 (if0) of the HA VPN gateway and the second VLAN attachment is assigned to interface 1 (if1).

Configure the HA VPN Cloud Router, peer VPN gateway resources, and HA VPN tunnels

Console

  1. In the Google Cloud console, continue to the next section of the HA VPN over Cloud Interconnect deployment wizard.

  2. In the Cloud Router section, select a Cloud Router. This router is dedicated to managing the BGP sessions for all of your HA VPN tunnels.

    You can use an existing Cloud Router if the router does not already manage a BGP session for a VLAN attachment associated with a Partner Interconnect connection.

    You cannot use the encrypted Cloud Router used for the Interconnect tier of your HA VPN over Cloud Interconnect deployment.

  3. If you do not have an available Cloud Router, select Create new router, and specify the following:

    • A name
    • An optional description

    • A Google ASN for the new router

      You can use any private ASN (64512 through 65534, 4200000000 through 4294967294) that you are not using elsewhere in your network. The Google ASN is used for all BGP sessions on the same Cloud Router, and you cannot change the ASN later.

    To create the new router, click Create.

  4. Configure the IKE version by selecting either IKEv1 or IKEv2. This version is used across all HA VPN tunnels in the deployment.

  5. Optional: Click Generate keys to generate the IKE pre-shared key for all VPN tunnels. If you select this option, the same IKE pre-shared key is populated for all tunnels across all HA VPN gateways. Make sure that you record the pre-shared key in a secure location because it cannot be retrieved after you create your VPN tunnels.

  6. In the VPN Configurations section, click a VPN configuration, and then specify the following:

    1. Peer VPN gateway: Select an existing peer VPN gateway, or create one by selecting Create a new peer VPN gateway. To create a peer VPN gateway, specify the following:

      • A name

      • Two interfaces

        If you need to specify a single interface or four interfaces, you cannot create this peer VPN gateway in the Google Cloud console. Use the Google Cloud CLI instead. Specifically, you must assign four interfaces on your peer VPN gateway if you are connecting to Amazon Web Services (AWS).

    2. In the IP addresses field, enter the IPv4 addresses of the two peer VPN gateway interfaces.

    3. Click Create.

  7. Under VPN Tunnel over ENCRYPTED VLAN_ATTACHMENT_1 and VPN Tunnel over ENCRYPTED VLAN_ATTACHMENT_2, configure the following fields for each tunnel:

    • Name: You can leave the generated tunnel name or modify it.
    • Description: Optional.
    • Associated peer VPN gateway interface: Select the peer VPN gateway interface and IP address combination that you want to associate with this tunnel and HA VPN interface. This interface must match the interface on your actual peer router.
    • IKE pre-shared key: If you did not already generate a pre-shared key for all tunnels, specify an IKE pre-shared key. Use the pre-shared key (shared secret) that corresponds with the pre-shared key that you create on your peer gateway. If you haven't configured a pre-shared key on your peer VPN gateway and want to generate one, click Generate and copy. Make sure that you record the pre-shared key in a secure location because it cannot be retrieved after you create your VPN tunnels.

  8. Click Done when you have completed the configuration of both tunnels.

  9. Repeat the previous two steps for each HA VPN gateway until you have configured all the gateways and their tunnels.

  10. If you need to add more tunnels, click Add VPN configuration and configure the following fields:

    1. VPN gateway: Select one of the HA VPN gateways that are associated with the encrypted VLAN attachments.

    2. Peer VPN gateway: Select an existing peer VPN gateway or create a new one by selecting Create a new peer VPN gateway. To create a new peer VPN gateway, specify the following:

      • A name
      • Two interfaces

      If you need to specify a single interface or four interfaces, you cannot create this peer VPN gateway in the Google Cloud console. Use the Google Cloud CLI instead. Specifically, you must assign four interfaces on your peer VPN gateway if you are connecting to AWS.

    3. In the IP addresses field, enter the IPv4 addresses of the two peer VPN gateway interfaces.

    4. Click Create.

  11. When you have finished configuring all your HA VPN tunnels, click Create and Continue.

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This router is dedicated to managing the BGP sessions for all of your HA VPN tunnels.

You can use an existing Cloud Router if the router does not already manage a BGP session for a VLAN attachment associated with a Partner Interconnect connection. You cannot use the encrypted Cloud Router used for the Cloud Interconnect tier of your HA VPN over Cloud Interconnect deployment.

  1. To create a Cloud Router, run the following command:

    gcloud compute routers create ROUTER_NAME \
   --region=REGION \
   --network=NETWORK \
   --asn=GOOGLE_ASN

    Replace the following:

    • ROUTER_NAME: the name of the Cloud Router in the same region as the Cloud VPN gateway
    • REGION: the Google Cloud region where you create the gateway and tunnel
    • NETWORK: the name of your Google Cloud network
    • GOOGLE_ASN: any private ASN (64512 through 65534, 4200000000 through 4294967294) that you are not already using in the peer network; the Google ASN is used for all BGP sessions on the same Cloud Router, and it cannot be changed later

    The router that you create should look similar to the following example output:

    Created [https://www.googleapis.com/compute/v1/projects/PROJECT_ID/regions/us-central1/routers/router-a].
NAME       REGION        NETWORK
router-a   us-central1   network-a

  2. Create at least one external peer VPN gateway.

    gcloud compute external-vpn-gateways create peer-gw \
   --interfaces 0=ON_PREM_GW_IP_0,1=ON_PREM_GW_IP_1

    Replace the following:

    • ON_PREM_GW_IP_0: the IP address assigned to interface 0 on your peer VPN gateway
    • ON_PREM_GW_IP_1: the IP address assigned to interface 1 on your peer VPN gateway

    Create as many external peer VPN gateways as needed in your deployment.

  3. For each HA VPN gateway that you created in Create HA VPN gateways, create a VPN tunnel for each interface, 0 and 1. In each command, you specify the peer side of the VPN tunnel as the external VPN gateway and interface that you created earlier.

    For example, to create four tunnels for the two example HA VPN gateways created in Create HA VPN gateways, run the following commands:

    gcloud compute vpn-tunnels create tunnel-a-to-on-prem-if-0 \
 --peer-external-gateway peer-gw \
 --peer-external-gateway-interface 0 \
 --region us-central1 \
 --ike-version 2 \
 --shared-secret SHARED_SECRET \
 --router vpn-router \
 --vpn-gateway vpn-gateway-a \
 --interface 0

    gcloud compute vpn-tunnels create tunnel-a-to-on-prem-if-1 \
 --peer-external-gateway peer-gw \
 --peer-external-gateway-interface 1 \
 --region us-central1 \
 --ike-version 2 \
 --shared-secret SHARED_SECRET \
 --router vpn-router \
 --vpn-gateway vpn-gateway-a \
 --interface 1

    gcloud compute vpn-tunnels create tunnel-b-to-on-prem-if-0 \
 --peer-external-gateway peer-gw \
 --peer-external-gateway-interface 0 \
 --region us-central1 \
 --ike-version 2 \
 --shared-secret SHARED_SECRET \
 --router vpn-router \
 --vpn-gateway vpn-gateway-b \
 --interface 0

    gcloud compute vpn-tunnels create tunnel-b-to-on-prem-if-1 \
 --peer-external-gateway peer-gw \
 --peer-external-gateway-interface 1 \
 --region us-central1 \
 --ike-version 2 \
 --shared-secret SHARED_SECRET \
 --router vpn-router \
 --vpn-gateway vpn-gateway-b \
 --interface 1

Configure BGP sessions

Console

In the Google Cloud console, continue to the next section of the HA VPN over Cloud Interconnect deployment wizard.

After you have created all the HA VPN tunnels, you must configure the BGP sessions for each tunnel.

Next to each tunnel, click Configure BGP session.

Follow the instructions in Create BGP sessions to configure BGP for each VPN tunnel.

gcloud

After you have created all the HA VPN tunnels, you must configure the BGP sessions for each tunnel.

For each tunnel, follow the instructions in Create BGP sessions.

Complete the HA VPN configuration

Before you can use the new Cloud VPN gateways and their associated VPN tunnels, complete the following steps:

  1. Set up the peer VPN gateways for your on-premises networks and configure the corresponding tunnels there. For instructions, see the following:
  2. Configure firewall rules in Google Cloud and your peer network as required.
  3. Check the status of your VPN tunnels. This step includes checking the high-availability configuration of your HA VPN gateway.

What's next?