Set up a regional external proxy Network Load Balancer with hybrid connectivity

An regional external proxy Network Load Balancer is a proxy-based regional Layer 4 load balancer that enables you to run and scale your TCP service traffic in a single region behind an external regional IP address. These load balancers distribute external TCP traffic from the internet to backends in the same region.

This page describes how to configure a regional external proxy Network Load Balancer to load balance traffic to backends in on-premises environments or in other cloud environments that are connected by using hybrid connectivity. Configuring hybrid connectivity to connect your networks to Google Cloud is not in scope for this page.

Before you begin, read the External proxy Network Load Balancer overview.

In this example, we'll use the load balancer to distribute TCP traffic across backend VMs located on-premises or in other cloud environments.

In this example, you configure the deployment shown in the following diagram.

External proxy Network Load Balancer example configuration with hybrid NEG backends.
External proxy Network Load Balancer example configuration with hybrid NEG backends

This is a regional load balancer. All load balancer components (backend instance group, backend service, target proxy, and forwarding rule) must be in the same region.

Permissions

To set up hybrid load balancing, you must have the following permissions:

  • On Google Cloud

    • Permissions to establish hybrid connectivity between Google Cloud and your on-premises environment or other cloud environments. For the list of permissions needed, see the relevant Network Connectivity product documentation.
    • Permissions to create a hybrid connectivity NEG and the load balancer. The Compute Load Balancer Admin role (roles/compute.loadBalancerAdmin) contains the permissions required to perform the tasks described in this guide.
  • On your on-premises environment or other non-Google Cloud cloud environment

    • Permissions to configure network endpoints that allow services on your on-premises environment or other cloud environments to be reachable from Google Cloud by using an IP:Port combination. For more information, contact your environment's network administrator.
    • Permissions to create firewall rules on your on-premises environment or other cloud environments to allow Google's health check probes to reach the endpoints.

Additionally, to complete the instructions on this page, you need to create a hybrid connectivity NEG, a load balancer, and zonal NEGs (and their endpoints) to serve as Google Cloud-based backends for the load balancer.

You should be either a project Owner or Editor, or you should have the following Compute Engine IAM roles.

Task Required role
Create networks, subnets, and load balancer components Compute Network Admin (roles/compute.networkAdmin)
Add and remove firewall rules Compute Security Admin (roles/compute.securityAdmin)
Create instances Compute Instance Admin (roles/compute.instanceAdmin)

Establish hybrid connectivity

Your Google Cloud and on-premises environment or other cloud environments must be connected through hybrid connectivity by using either Cloud Interconnect VLAN attachments or Cloud VPN tunnels with Cloud Router. We recommend that you use a high availability connection.

A Cloud Router enabled with global dynamic routing learns about the specific endpoint through Border Gateway Protocol (BGP) and programs it into your Google Cloud VPC network. Regional dynamic routing is not supported. Static routes are also not supported.

The VPC network that you use to configure either Cloud Interconnect or Cloud VPN is the same network that you use to configure the hybrid load balancing deployment. Ensure that your VPC network's subnet CIDR ranges do not conflict with your remote CIDR ranges. When IP addresses overlap, subnet routes are prioritized over remote connectivity.

For instructions, see the following documentation:

Set up your environment that is outside Google Cloud

Perform the following steps to set up your on-premises environment or other cloud environment for hybrid load balancing:

  • Configure network endpoints to expose on-premises services to Google Cloud (IP:Port).
  • Configure firewall rules on your on-premises environment or other cloud environment.
  • Configure Cloud Router to advertise certain required routes to your private environment.

Set up network endpoints

After you set up hybrid connectivity, you configure one or more network endpoints within your on-premises environment or other cloud environments that are reachable through Cloud Interconnect or Cloud VPN by using an IP:port combination. This IP:port combination is configured as one or more endpoints for the hybrid connectivity NEG that is created in Google Cloud later on in this process.

If there are multiple paths to the IP endpoint, routing follows the behavior described in the Cloud Router overview.

Set up firewall rules

The following firewall rules must be created on your on-premises environment or other cloud environment:

  • Create an ingress allow firewall rule in on-premises or other cloud environments to allow traffic from the region's proxy-only subnet to reach the endpoints.
  • Allowlisting Google's health check probe ranges isn't required for hybrid NEGs. However, if you're using a combination of hybrid and zonal NEGs in a single backend service, you need to allowlist the Google health check probe ranges for the zonal NEGs.

Configure Cloud Router to advertise the following custom IP ranges to your on-premises environment or other cloud environment:

  • The range of the region's proxy-only subnet.

Set up your Google Cloud environment

For the following steps, make sure that you use the same VPC network (called NETWORK in this procedure) that was used to configure hybrid connectivity between the environments. You can select any subnet from this network to reserve the load balancer's IP address and create the load balancer. This subnet is referred to as LB_SUBNET in this procedure.

Additionally, make sure that the region used (called REGION in this procedure) is the same region that was used to create the Cloud VPN tunnel or Cloud Interconnect VLAN attachment.

Configure the proxy-only subnet

A proxy-only subnet provides a set of IP addresses that Google uses to run Envoy proxies on your behalf. The proxies terminate connections from the client and create new connections to the backends.

This proxy-only subnet is used by all Envoy-based regional load balancers in the region (REGION) of the VPC network (NETWORK).

There can only be one active proxy-only subnet per region, per VPC network. You can skip this step if there's already a proxy-only subnet in this region.

Console

If you're using the Google Cloud console, you can wait and create the proxy-only subnet later on the Load balancing page.

If you want to create the proxy-only subnet now, use the following steps:

  1. In the Google Cloud console, go to the VPC networks page.

    Go to VPC networks

  2. Go to the network that was used to configure hybrid connectivity between the environments.

  3. Click Add subnet.

  4. For Name, enter proxy-only-subnet.

  5. For Region, select us-west1.

  6. Set Purpose to Regional Managed Proxy.

  7. For IP address range, enter 10.129.0.0/23.

  8. Click Add.

gcloud

To create the proxy-only subnet, use the gcloud compute networks subnets create command:

gcloud compute networks subnets create proxy-only-subnet \
    --purpose=REGIONAL_MANAGED_PROXY \
    --role=ACTIVE \
    --region=us-west1 \
    --network=NETWORK \
    --range=10.129.0.0/23

Reserve the load balancer's IP address

Reserve an external IP address for the load balancer. This procedure creates the load balancer's IP address in Standard Tier. Regional external proxy Network Load Balancers support both the Premium and Standard Network Service Tiers. However, creating this load balancer in the Premium Tier is not supported in the Google Cloud console. Use either gcloud or the REST API instead.

Console

  1. In the Google Cloud console, go to the Reserve a static address page.

    Go to Reserve a static address

  2. Choose a name for the new address.

  3. For Network Service Tier, select Standard.

  4. For IP version, select IPv4. IPv6 addresses are not supported.

  5. For Type, select Regional.

  6. For Region, select us-west1.

  7. Leave the Attached to option set to None. After you create the load balancer, this IP address is attached to the load balancer's forwarding rule.

  8. Click Reserve to reserve the IP address.

gcloud

  1. To reserve a static external IP address, use the gcloud compute addresses create command:

    gcloud compute addresses create ADDRESS_NAME  \
       --region=us-west1 \
       --network-tier=STANDARD
    

    Replace ADDRESS_NAME with the name that you want to call this address.

  2. To view the result, use the gcloud compute addresses describe command:

    gcloud compute addresses describe ADDRESS_NAME
    

Set up the hybrid connectivity NEG

When you create the NEG, use a ZONE that minimizes the geographic distance between Google Cloud and your on-premises or other cloud environment. For example, if you are hosting a service in an on-premises environment in Frankfurt, Germany, you can specify the europe-west3-a Google Cloud zone when you create the NEG.

Moreover, the zone that you use to create the NEG should be in the same region where the Cloud VPN tunnel or the Cloud Interconnect VLAN attachment was configured for hybrid connectivity.

For the available regions and zones, see Available regions and zones in the Compute Engine documentation.

Console

Create a hybrid connectivity NEG

  1. In the Google Cloud console, go to the Network endpoint groups page.

    Go to Network endpoint groups

  2. Click Create network endpoint group.

  3. For Name, enter HYBRID_NEG_NAME.

  4. For Network endpoint group type, select Hybrid connectivity network endpoint group (Zonal).

  5. For Network, select NETWORK.

  6. For Subnet, select LB_SUBNET.

  7. For Zone, select HYBRID_NEG_ZONE.

  8. For Default port, select the default.

  9. For Maximum connections, enter 2.

  10. Click Create.

Add endpoints to the hybrid connectivity NEG

  1. In the Google Cloud console, go to the Network endpoint groups page.

    Go to Network endpoint groups

  2. Click the name of the network endpoint group that you created in the previous step (HYBRID_NEG_NAME).

  3. On the Network endpoint group details page, in the Network endpoints in this group section, click Add network endpoint.

  4. On the Add network endpoint page, enter the IP address of the new network endpoint.

  5. Select the Port type:

    • If you select Default, the endpoint uses the default port for all endpoints in the network endpoint group.
    • If you select Custom, you can enter a different port number for the endpoint to use.
  6. To add more endpoints, click Add network endpoint and repeat the previous steps.

  7. After you add all the non-Google Cloud endpoints, click Create.

gcloud

  1. To create a hybrid connectivity NEG, use the gcloud compute network-endpoint-groups create command:

    gcloud compute network-endpoint-groups create HYBRID_NEG_NAME \
        --network-endpoint-type=NON_GCP_PRIVATE_IP_PORT \
        --zone=HYBRID_NEG_ZONE \
        --network=NETWORK
     
  2. Add the on-premises IP:Port endpoint to the hybrid NEG:

    gcloud compute network-endpoint-groups update HYBRID_NEG_NAME \
        --zone=HYBRID_NEG_ZONE \
        --add-endpoint="ip=ENDPOINT_IP_ADDRESS,port=ENDPOINT_PORT"
    

You can use this command to add the network endpoints that you previously configured on-premises or in your cloud environment. Repeat --add-endpoint as many times as needed.

You can repeat these steps to create multiple hybrid NEGs if needed.

Configure the load balancer

Console

Start the configuration

  1. In the Google Cloud console, go to the Load balancing page.

    Go to Load balancing

  2. Click Create load balancer.

  3. On the Network Load Balancer (TCP/SSL) card, click Start configuration.
  4. For Internet facing or internal only, select From Internet to my VMs.

  5. For Multiple regions or single region, select Single region.

  6. For Load balancer type, select Proxy.

  7. Click Continue.

  8. For Name, enter a name for the load balancer.

  9. For Region, select REGION.

  10. For Network, select NETWORK.

Reserve a proxy-only subnet

  1. Click Reserve subnet.
  2. For Name, enter proxy-only-subnet.
  3. For IP address range, enter 10.129.0.0/23.
  4. Click Add.

Configure the backend

  1. Click Backend configuration.
  2. For Backend type, select Hybrid connectivity network endpoint group (Zonal).
  3. For Protocol, select TCP.
  4. For New backend, select the hybrid NEG that you created previously (HYBRID_NEG_NAME). Or, you can click Create a network endpoint group to create the hybrid NEG now. For guidance about configuring the NEG, see Set up the hybrid NEG.
  5. Retain the remaining default values, and then click Done.
  6. Configure the health check:
    • For Health check, select Create a health check.
    • For Name, enter a name for the health check.
    • For Protocol, select TCP.
    • For Port, enter 80.
  7. Retain the remaining default values, and then click Save.
  8. In the Google Cloud console, verify that there is a check mark next to Backend configuration. If not, double-check that you have completed all of the steps.

Configure the frontend

  1. Click Frontend configuration.
  2. For Name, enter a name for the forwarding rule.
  3. For IP address, select LB_IP_ADDRESS.
  4. For Port number, enter any port number from 1-65535. The forwarding rule only forwards packets with a matching destination port.
  5. Enable Proxy protocol only if it works with the service running on your on-premises or other cloud endpoints. For example, PROXY protocol doesn't work with the Apache HTTP Server software. For more information, see PROXY protocol.
  6. Click Done.
  7. In the Google Cloud console, verify that there is a check mark next to Frontend configuration. If not, double-check that you have completed all the previous steps.

Review and finalize

  1. Click Review and finalize.
  2. Double-check your settings.
  3. Click Create.

gcloud

  1. Create a regional health check for the backends:

    gcloud compute health-checks create tcp TCP_HEALTH_CHECK_NAME \
        --region=REGION \
        --use-serving-port
    
  2. Create a backend service:

    gcloud compute backend-services create BACKEND_SERVICE_NAME \
       --load-balancing-scheme=EXTERNAL_MANAGED \
       --protocol=TCP \
       --region=REGION \
       --health-checks=TCP_HEALTH_CHECK_NAME \
       --health-checks-region=REGION
    
  3. Add the hybrid NEG backend to the backend service:

    gcloud compute backend-services add-backend BACKEND_SERVICE_NAME \
       --network-endpoint-group=HYBRID_NEG_NAME \
       --network-endpoint-group-zone=HYBRID_NEG_ZONE \
       --region=REGION \
       --balancing-mode=CONNECTION \
       --max-connections=MAX_CONNECTIONS
    

    For MAX_CONNECTIONS, enter the maximum concurrent connections that the backend should handle.

  4. Create the target TCP proxy:

    gcloud compute target-tcp-proxies create TARGET_TCP_PROXY_NAME \
       --backend-service=BACKEND_SERVICE_NAME \
       --region=REGION
    
  5. Create the forwarding rule. Use the gcloud compute forwarding-rules create command. Replace FWD_RULE_PORT with a single port number from 1-65535. The forwarding rule only forwards packets with a matching destination port.

    gcloud compute forwarding-rules create FORWARDING_RULE \
       --load-balancing-scheme=EXTERNAL_MANAGED \
       --network=NETWORK \
       --subnet=LB_SUBNET \
       --address=LB_IP_ADDRESS \
       --ports=FWD_RULE_PORT \
       --region=REGION \
       --target-tcp-proxy=TARGET_TCP_PROXY_NAME \
       --target-tcp-proxy-region=REGION
    

Test your load balancer

Now that you have configured your load balancer, you can test sending traffic to the load balancer's IP address.

  1. Get the load balancer's IP address.

    To get the IPv4 address, run the following command:

    gcloud compute addresses describe ADDRESS_NAME
    
  2. Send traffic to your load balancer by running the following command. Replace LB_IP_ADDRESS with your load balancer's IPv4 address.

    curl -m1 LB_IP_ADDRESS:FWD_RULE_PORT
    

What's next