Configure global network firewall policy to deny egress connections to specific geolocations

This tutorial describes how to create and configure a global network firewall policy to block egress traffic to specific geolocations in your network. It walks through an example of creating a Virtual Private Cloud (VPC) network with two subnets, setting up a firewall policy with geolocation firewall rules, and then testing the firewall rules.

Objectives

This tutorial shows you how to complete the following tasks:

  • Create a custom VPC network with two subnets in different regions.
  • Create a virtual machine (VM) instance in each of the following regions: the US and Singapore.
  • Create a Cloud Router and a Cloud NAT gateway, to allow the US VM to access the public internet.
  • Create a global network firewall policy and add a firewall rule to enable Identity-Aware Proxy (IAP).
  • Install Apache server on the Singapore VM.
  • Add a firewall rule to block traffic to specific geolocations.
  • Test the geolocation firewall rule.

The following diagram shows traffic between VMs in theus-central1 and asia-southeast1 regions within a custom VPC network. A global network firewall policy blocks egress traffic to a specific geolocation. The VM in the us-central1 region uses Cloud Router and a Cloud NAT for internet access, without using an external IP address. The VM in the us-central1 region uses the external IP address of the VM in the asia-southeast1 region to test the firewall rule.

A global network firewall policy blocking egress traffic from a subnet to a specific geolocation.
A global network firewall policy blocking egress traffic from a subnet to a specific geolocation (click to enlarge).

Before you begin

  • Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

  • In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Roles required to select or create a project

    • Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
    • Create a project: To create a project, you need the Project Creator (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

    Go to project selector

  • Verify that billing is enabled for your Google Cloud project.

  • In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Roles required to select or create a project

    • Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
    • Create a project: To create a project, you need the Project Creator (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

    Go to project selector

  • Verify that billing is enabled for your Google Cloud project.

  • Make sure that you have the Compute Network Admin role (roles/compute.networkAdmin).

  • Enable the Compute Engine and Identity-Aware Proxy (IAP) APIs.

    Roles required to enable APIs

    To enable APIs, you need the Service Usage Admin IAM role (roles/serviceusage.serviceUsageAdmin), which contains the serviceusage.services.enable permission. Learn how to grant roles.

    Enable the APIs

  • If you prefer to work from the command line, install the Google Cloud CLI. For the conceptual and installation information about the tool, see gcloud CLI overview.

    Note: If you haven't run the Google Cloud CLI previously, initialize your gcloud CLI directory by running the gcloud init command.

Create a custom VPC network with subnets

Create a custom mode VPC network with two IPv4 subnets.

Console

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

    Go to VPC networks

  2. Click Create VPC network.

  3. For Name, enter vpc-geo-location.

  4. For Subnet creation mode, select Custom.

  5. In the New subnet section, specify the following configuration parameters for a subnet:

    • Name: subnet-1-us
    • Region: us-central1
    • IPv4 range: 10.0.0.0/24

  6. Click Done.

  7. Click Add subnet and specify the following configuration parameters:

    • Name: subnet-2-sg
    • Region: asia-southeast1
    • IPv4 range: 192.168.200.0/24

  8. Click Done.

  9. Click Create.

gcloud

  1. To open the terminal, click Activate Cloud Shell.

  2. To create a VPC network, run the following command:

     gcloud compute networks create vpc-geo-location \ --subnet-mode=custom

  3. In the Authorize cloud shell dialog, click Authorize.

  4. To create a subnet, run the following command:

     gcloud compute networks subnets create subnet-1-us \ --network=vpc-geo-location \ --region=us-central1 \ --range=10.0.0.0/24

  5. To create another subnet, run the following command:

     gcloud compute networks subnets create subnet-2-sg \ --network=vpc-geo-location \ --region=asia-southeast1 \ --range=192.168.200.0/24

Create VMs

In this section, you create two VMs in the subnets you configured in the preceding section.

Create a VM in the us-central1 region

Create a VM in the us-central1 region without an external IP address.

Console

To create a VM in the us-central1 region, follow these steps:

  1. In the Google Cloud console, go to the Create an instance page.

    Go to Create an instance

  2. In the Machine configuration pane, do the following:

    1. For Name, enter instance-1-us.
    2. For Region, select us-central1 (Iowa).

  3. In the navigation menu, click Networking.

    1. In the Network interfaces section, click default and specify the following configuration parameters:
      • Network: vpc-geo-location
      • Subnetwork: subnet-1-us IPv4 (10.0.0.0/24)
      • External IPv4 address: None
    2. Click Done.

  4. Click Create.

gcloud

To create a VM in the us-central1 region, run the following command:

 gcloud compute instances create instance-1-us \ --network=vpc-geo-location \ --zone=us-central1-a \ --stack-type=IPV4_ONLY \ --no-address \ --subnet=subnet-1-us

Create a VM in the asia-southeast1 region

Console

To create a VM in the asia-southeast1 region, follow these steps:

  1. In the Google Cloud console, go to the Create an instance page.

    Go to Create an instance

  2. In the Machine configuration pane, do the following:

    1. For Name, enter instance-2-sg.
    2. For Region, select asia-southeast1 (Singapore).

  3. In the navigation menu, click Networking.

    1. In the Network interfaces section, click default and specify the following configuration parameters:
      • Network: vpc-geo-location
      • Subnetwork: subnet-2-sg IPv4 (192.168.200.0/24)
      • External IPv4 address: None
    2. Click Done.

  4. Click Create.

gcloud

To create a VM in the asia-southeast1 region, run the following command:

 gcloud compute instances create instance-2-sg \ --network=vpc-geo-location \ --zone=asia-southeast1-b \ --subnet=subnet-2-sg \ --stack-type=IPV4_ONLY

Create a Cloud Router and a Cloud NAT gateway

In the previous section, you created two VMs, instance-1-us and asia-southeast1. To allow instance-1-us VMs to access the public internet, create a Cloud Router and a Cloud NAT gateway.

Console

  1. In the Google Cloud console, go to the Cloud NAT page.

    Go to Cloud NAT

  2. Click Get started or Create Cloud NAT gateway.

  3. For Gateway name, enter nat-gateway.

  4. For NAT type, select Public.

  5. In the Select Cloud Router section, specify the following configuration parameters:

    • Network: vpc-geo-location
    • Region: us-central1
    • Cloud Router: Create new router.
      1. For Name, enter router-fw-rules.
      2. Click Create.

  6. Click Create.

  7. In the Google Cloud console, go to the IP addresses page.

    Go to IP addresses

  8. Click the External IP Addresses tab, and then copy the IP address of your Cloud NAT (nat-auto-ip). This IP address is used when you validate the connection between the instance-1-us VM and instance-2-sg VM.

gcloud

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

     gcloud compute routers create router-fw-rules \ --network=vpc-geo-location \ --region=us-central1

  2. To create a Cloud NAT gateway, run the following command:

     gcloud compute routers nats create nat-gateway \ --router=router-fw-rules \ --region=us-central1 \ --auto-allocate-nat-external-ips \ --nat-all-subnet-ip-ranges

  3. To view the Cloud NAT IP address, run the following command:

     gcloud compute routers get-nat-ip-info \ router-fw-rules \ --region=us-central1

    Remember to copy the IP address of your Cloud NAT (natIp). This IP address is used when you validate the connection between the instance-1-us VM and the instance-2-sg VM.

Create a global network firewall policy to enable IAP

In this section, you create a global network firewall policy and add a firewall rule to enable IAP. IAP allows administrative access to the VM instances.

The firewall rule includes the following characteristics.

  • Ingress traffic from IP range 35.235.240.0/20. This range contains all IP addresses that IAP uses for TCP forwarding.

  • A connection to all ports that you want to be accessible by using IAP TCP forwarding, for example, port 22 for SSH.

Console

To allow IAP access to all VM instances in the vpc-geo-location network, follow these steps:

  1. In the Google Cloud console, go to the Firewall policies page.

    Go to Firewall policies

  2. Click Create firewall policy.

  3. In the Configure policy section, for Policy name, enter fw-policy.

  4. For Deployment scope, select Global and click Continue.

  5. To create rules for your policy, in the Add rules section, click Add rule.

    1. For Priority, enter 100.
    2. For Direction of traffic, select Ingress.
    3. For Action on match, select Allow.
    4. For Logs, select On.
    5. In the Target section, for Target type, select All instances in the network.
    6. In the Source section, for IP ranges, enter 35.235.240.0/20.
    7. In the Protocol and ports section, select Specified protocols and ports.
    8. Select the TCP checkbox, and for Ports, enter 22.
    9. Click Create.

  6. Click Continue.

  7. To associate a VPC network with the policy, in the Associate policy with VPC networks section, click Associate.

  8. Select the checkbox of vpc-geo-location and click Associate.

  9. Click Continue.

  10. Click Create.

gcloud

To allow IAP access to all VM instances in the vpc-geo-location network, run the following command:

  1. To create a firewall policy, run the following command:

     gcloud compute network-firewall-policies create fw-policy \ --global

  2. To create a firewall rule that allows traffic to all destinations and enables logs, run the following command:

     gcloud compute network-firewall-policies rules create 100 \ --firewall-policy=fw-policy \ --direction=INGRESS \ --action=ALLOW \ --layer4-configs=tcp:22 \ --src-ip-ranges=35.235.240.0/20 \ --global-firewall-policy \ --enable-logging

  3. To associate the firewall policy with the VPC network, run the following command:

     gcloud compute network-firewall-policies associations create \ --firewall-policy=fw-policy \ --network=vpc-geo-location \ --name=pol-association-fw-rules \ --global-firewall-policy

Create a firewall rule

In this section, you create a firewall rule to allow ingress connection on the instance-2-sg VM.

Console

  1. In the Google Cloud console, go to the Firewall policies page.

    Go to Firewall policies

  2. In the Network firewall policies section, click fw-policy.

  3. Click Create rule.

  4. For Priority, enter 500.

  5. For Direction of traffic, select Ingress.

  6. For Action on match, select Allow.

  7. For Logs, select On.

  8. In the Target section, for Target type, select All instances in the network.

  9. In the Source section, for IP ranges, enter NAT_IP_ADDRESS.

    Replace NAT_IP_ADDRESS with the IP address assigned to your Cloud NAT. For more information, see Create a Cloud Router and a Cloud NAT gateway.

  10. Click Create.

gcloud

To update the firewall policy, run the following command:

 gcloud compute network-firewall-policies rules create 500 \ --firewall-policy=fw-policy \ --direction=INGRESS \ --action=ALLOW \ --src-ip-ranges=NAT_IP_ADDRESS \ --layer4-configs=all \ --global-firewall-policy \ --enable-logging

Replace NAT_IP_ADDRESS with the IP address assigned to your Cloud NAT. For more information, see Create a Cloud Router and a Cloud NAT gateway.

Install the Apache server

In this section, you install the Apache server on the instance-2-sg VM.

Console

  1. In the Google Cloud console, go to the VM instances page.

    Go to VM instances

  2. In the Connect column of the instance-2-sg VM, click SSH.

  3. In the SSH-in-browser dialog, click Authorize and wait for the connection to establish.

  4. To update the package lists on your instance, run the following command:

     sudo apt-get update

    When the process is finished, it generates the following message:

    Reading package lists... Done.

  5. To install the apache2 HTTP Server package, at the command prompt, run the following command:

     sudo apt-get install apache2 php7.0

    While the process is in progress, it generates the following message:

    After this operation, 56.0 MB of additional disk space will be used. Do you want to continue? [Y/n]

    Press Y to confirm, and then press Enter.

  6. To overwrite the Apache web server default web page, run the following command:

    echo '<!doctype html><html><body><h1>Hello World!</h1></body></html>' | sudo tee /var/www/html/index.html

  7. Close the SSH-in-browser dialog.

gcloud

  1. To use SSH to connect to the instance-2-sg VM, run the following command:

     gcloud compute ssh instance-2-sg \ --zone=asia-southeast1-b \ --tunnel-through-iap

    When prompted, press Y to confirm, and then press Enter.

  2. To update the package lists on your instance, run the following command:

     sudo apt-get update

    When the process is finished, it generates the following message:

    Reading package lists... Done.

  3. To install the apache2 HTTP Server package, at the command prompt, run the following command:

     sudo apt-get install apache2 php7.0

    While the process is in progress, it generates the following message:

    After this operation, 56.0 MB of additional disk space will be used. Do you want to continue? [Y/n]

    Press Y to confirm, and then press Enter.

  4. To overwrite the Apache web server default web page, run the following command:

    echo '<!doctype html><html><body><h1>Hello World!</h1></body></html>' | sudo tee /var/www/html/index.html

  5. To close the SSH-in-browser, enter exit.

Validate the connection

After installing the Apache server on the instance-2-sg VM, connect to the instance-1-us VM from the instance-2-sg VM using the external IP address of the instance-2-sg VM.

Console

  1. In the Google Cloud console, go to the VM instances page.

    Go to VM instances

  2. From the External IP column of the instance-2-sg VM, copy the external IP address of the VM.

  3. In the Connect column of the instance-1-us VM, click SSH.

  4. In the SSH-in-browser dialog, click Authorize and wait for the connection to establish.

  5. To verify the connection, run the following command:

     curl EXTERNAL_IP -m 2

    Replace EXTERNAL_IP with the IP address of the instance-2-sg VM.

    The expected response message is as follows:

    <!doctype html><html><body><h1>Hello World!</h1></body></html>

  6. Close the SSH-in-browser dialog.

gcloud

  1. To view the external IP address of the instance-2-sg VM, run the following command:

     gcloud compute instances describe instance-2-sg \ --zone=asia-southeast1-b \ --format='get(networkInterfaces[0].accessConfigs[0].natIP)'

    When prompted, press Y to confirm, and then press Enter. Make sure to note the external IP address of the instance-2-sg VM.

  2. To use SSH to connect to the instance-1-us VM, run the following command:

     gcloud compute ssh instance-1-us \ --zone=us-central1-a \ --tunnel-through-iap

  3. To verify the connection, run the following command:

     curl EXTERNAL_IP -m 2

    Replace EXTERNAL_IP with the IP address of the instance-2-sg VM.

    The expected response message is as follows:

    <!doctype html><html><body><h1>Hello World!</h1></body></html>

  4. To close the SSH-in-browser, enter exit.

Add a firewall rule to block traffic to specific geolocations

In this section you add a firewall rule for the VPC vpc-geo-location to block egress traffic to Italy, Poland, and Singapore.

Console

To add a new rule in the fw-policy that you created in the Create a global network firewall policy section, follow these steps:

  1. In the Google Cloud console, go to the Firewall policies page.

    Go to Firewall policies

  2. In the Network firewall policies section, click fw-policy.

  3. Click Create rule.

  4. For Priority, enter 200.

  5. For Direction of traffic, select Egress.

  6. For Action on match, select Deny.

  7. For Logs, select On.

  8. In the Destination section, for Geolocations, select Singapore (SG), Poland (PL), and Italy (IT).

  9. Click OK.

  10. Click Create.

gcloud

To add a new rule in the fw-policy that you created in the Create a global network firewall policy section, run the following command:

 gcloud compute network-firewall-policies rules create 200 \ --firewall-policy=fw-policy \ --direction=EGRESS \ --action=DENY \ --dest-region-codes=SG,PL,IT \ --layer4-configs=all \ --global-firewall-policy \ --enable-logging

Test the geolocation firewall rule

Console

After you have added the rule to block egress traffic to Singapore (SG), Poland (PL), and Italy (IT), follow these steps to test the rule:

  1. In the Google Cloud console, go to the VM instances page.

    Go to VM instances

  2. From the External IP column of the instance-2-sg VM, copy the external IP address of the VM.

  3. In the Connect column of the instance-1-us VM, click SSH.

  4. In the SSH-in-browser dialog, click Authorize and wait for the connection to establish.

  5. To verify that egress traffic to the instance-2-sg VM is blocked, run the following command:

     curl EXTERNAL_IP -m 2

    Replace EXTERNAL_IP with the IP address of the instance-2-sg VM.

    The Connection timed out message is expected because you created a firewall rule to deny external traffic from the US VM to the Singapore VM.

  6. To verify that the egress traffic to Poland is blocked, run the following command:

     curl `https://www.gov.pl` -m 2

    The Connection timed out message is expected because you created a firewall rule to deny external traffic to the Poland website.

  7. To verify that the egress traffic to Italy is blocked, run the following command:

     curl `https://www.esteri.it/it/` -m 2

    The Connection timed out message is expected because you created a firewall rule to deny external traffic to the Italy website.

  8. Close the SSH-in-browser dialog.

gcloud

After you have added the rule to block egress traffic to Singapore (SG), Poland (PL), and Italy (IT), run the following command to test the rule:

  1. To view the external IP address of the instance-2-sg VM, run the following command:

     gcloud compute instances describe instance-2-sg \ --format='get(networkInterfaces[0].accessConfigs[0].natIP)'

    When prompted, press Y to confirm, and then press Enter. Make sure to note the external IP address of the instance-2-sg VM.

  2. To use SSH to connect to the instance-1-us VM, run the following command:

     gcloud compute ssh instance-1-us \ --zone=us-central1-a \ --tunnel-through-iap

  3. To verify that the egress traffic to Singapore is blocked, run the following command:

     curl EXTERNAL_IP -m 2

    Replace EXTERNAL_IP with the IP address of the instance-2-sg VM.

    The Connection timed out message is expected because you created a firewall rule to deny external traffic from the US VM to the Singapore VM.

  4. To verify that the egress traffic to Poland is blocked, run the following command:

     curl https://www.gov.pl -m 2

    The Connection timed out message is expected because you created a firewall rule to deny external traffic from the Poland website.

  5. To verify that the egress traffic to Italy is blocked, run the following command:

     curl https://www.esteri.it/it/ -m 2

    The Connection timed out message is expected because you created a firewall rule to deny external traffic to the Italy website.

  6. To close the SSH-in-browser dialog, enter exit.

View the logs

You can verify that the firewall rules were applied to the egress traffic by accessing the logs. To view the log details, follow these steps:

  1. In the Google Cloud console, go to the Firewall policies page.

    Go to Firewall policies

  2. In the Network firewall policies section, click the fw-policy name.

  3. Click Column display options.

  4. In the Displayed columns dialog, select Hit count and then click OK.

  5. In the Hit count column, select the number for the rule you created during Create a global network firewall policy. The Logs Explorer page opens.

  6. To view the firewall rule applied to the egress traffic, expand the individual log. You can view the connection, disposition, and remote location details.

Clean up

To avoid incurring charges to your Google Cloud account for the resources used in this tutorial, either delete the project that contains the resources, or keep the project and delete the individual resources.

In this section, you delete the resources created in this tutorial.

Delete the firewall policy

Console

  1. In the Google Cloud console, go to the Firewall policies page.

    Go to Firewall policies

  2. In the Network firewall policies section, click the fw-policy name.

  3. Click the Associations tab.

  4. Select the checkbox of vpc-geo-location and click Remove association.

  5. In the Remove a firewall policy association dialog, click Remove.

  6. Next to the fw-policy title, click Delete.

  7. In the Delete a firewall policy dialog, click Delete.

gcloud

  1. Remove the association between the firewall policy and VPC network.

     gcloud compute network-firewall-policies associations delete \ --name=pol-association-fw-rules \ --firewall-policy=fw-policy \ --global-firewall-policy

  2. Delete the firewall policy.

     gcloud compute network-firewall-policies delete fw-policy \ --global

    When prompted, press Y to confirm, and then press Enter.

Delete the VMs

Console

  1. In the Google Cloud console, go to the VM instances page.

    Go to VM instances

  2. Select the checkboxes of instance-1-us and instance-2-sg VMs.

  3. Click Delete.

  4. In the Delete 2 instances? dialog, click Delete.

gcloud

  1. To delete the instance-1-us VM, run the following command:

     gcloud compute instances delete instance-1-us \ --zone=us-central1-a

    When prompted, press Y to confirm, and then press Enter.

  2. To delete the instance-2-sg VM, run the following command:

     gcloud compute instances delete instance-2-sg \ --zone=asia-southeast1-b

    When prompted, press Y to confirm, and then press Enter.

Delete the Cloud NAT gateway and Cloud Router

Console

  1. In the Google Cloud console, go to the Cloud routers page.

    Go to Cloud routers

  2. Select the router-fw-rules checkbox.

  3. Click Delete.

  4. In the Delete router-fw-rules dialog, click Delete.

When you delete a Cloud Router, the associated Cloud NAT gateway is also deleted.

gcloud

To delete the router-fw-rules Cloud Router, run the following command:

 gcloud compute routers delete router-fw-rules \ --region=us-central1

When prompted, press Y to confirm, and then press Enter.

When you delete a Cloud Router, the associated Cloud NAT gateway is also deleted.

Delete the VPC network and its subnets

Console

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

    Go to VPC networks

  2. In the Name column, click vpc-geo-location.

  3. Click Delete VPC network.

  4. In the Delete a network dialog, click Delete.

When you delete a VPC, its subnets are also deleted.

gcloud

  1. To delete the subnet subnet-1-us of the vpc-geo-location VPC network, run the following command:

     gcloud compute networks subnets delete subnet-1-us \ --region=us-central1

    When prompted, press Y to confirm, and then press Enter.

  2. To delete the subnet subnet-2-sg of the vpc-geo-location VPC network, run the following command:

     gcloud compute networks subnets delete subnet-2-sg \ --region=asia-southeast1

    When prompted, press Y to confirm and press Enter.

  3. To delete the vpc-geo-location VPC network, run the following command:

     gcloud compute networks delete vpc-geo-location

    When prompted, press Y to confirm, and then press Enter.

What's next