{"id":49317,"date":"2025-05-13T08:07:07","date_gmt":"2025-05-13T08:07:07","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=49317"},"modified":"2025-05-13T08:07:07","modified_gmt":"2025-05-13T08:07:07","slug":"what-is-google-cloud-nat","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/what-is-google-cloud-nat\/","title":{"rendered":"What is Google Cloud NAT?"},"content":{"rendered":"\n
\n\n\n\n

\ud83d\ude80 What is Google Cloud NAT?<\/h2>\n\n\n\n

Google Cloud NAT (Network Address Translation)<\/strong> is a fully managed service<\/strong> that enables outbound internet connectivity<\/strong> for resources in private Google Cloud VPC subnets<\/strong>, without requiring external IP addresses<\/strong>.<\/p>\n\n\n\n

\n

In simpler terms: Cloud NAT lets VMs without public IPs<\/strong> access the internet (e.g., to install updates or contact APIs), while remaining inaccessible from the outside<\/strong>.<\/p>\n<\/blockquote>\n\n\n\n

\n\n\n\n

\ud83e\udde0 Why Use Cloud NAT?<\/h2>\n\n\n\n
    \n
  • Secure internet access<\/strong> from private subnets<\/strong><\/li>\n\n\n\n
  • No need for bastion hosts<\/strong> or manual NAT gateways<\/strong><\/li>\n\n\n\n
  • Supports Compute Engine<\/strong>, GKE nodes<\/strong>, Cloud Run VPC connectors<\/strong><\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n

    \ud83c\udf1f Key Features of Cloud NAT<\/h2>\n\n\n\n
    Feature<\/th>Description<\/th><\/tr><\/thead>
    No external IPs required<\/strong><\/td>VMs stay private but still access the internet<\/td><\/tr>
    Managed Service<\/strong><\/td>No need to configure or maintain NAT instances<\/td><\/tr>
    Scalability<\/strong><\/td>Automatically scales to meet connection demand<\/td><\/tr>
    High Availability<\/strong><\/td>Fully distributed across zones with regional failover<\/td><\/tr>
    Logging & Monitoring<\/strong><\/td>Integrated with Cloud Logging and Cloud Monitoring<\/td><\/tr>
    Per Subnet & Per Instance Controls<\/strong><\/td>Choose which VMs or subnets are NATed<\/td><\/tr>
    Static IP support<\/strong><\/td>Option to use reserved static IPs for egress<\/td><\/tr>
    Port Allocation Options<\/strong><\/td>Manual or automatic port management per VM<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    \n\n\n\n

    \ud83d\udd10 Use Cases<\/h2>\n\n\n\n
    Use Case<\/th>Description<\/th><\/tr><\/thead>
    Private GKE Clusters<\/strong><\/td>Let GKE nodes access the internet without public IPs<\/td><\/tr>
    Private Compute VMs<\/strong><\/td>Allow package updates or API calls while remaining internal<\/td><\/tr>
    Secure Outbound API Access<\/strong><\/td>Talk to third-party APIs without exposing VMs<\/td><\/tr>
    Avoiding External Attack Surface<\/strong><\/td>Keep services invisible to external scanning tools<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    \n\n\n\n

    \ud83e\uddf0 How to Set Up Cloud NAT \u2014 Step-by-Step Tutorial<\/h2>\n\n\n\n

    \ud83e\uddfe Prerequisites<\/h3>\n\n\n\n
      \n
    • A GCP project with billing enabled<\/li>\n\n\n\n
    • A VPC with at least one private subnet<\/strong><\/li>\n\n\n\n
    • Compute Engine or GKE nodes without public IPs<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n

      \u2705 Step 1: Reserve an External Static IP (Optional)<\/h3>\n\n\n
      gcloud compute addresses create nat-ip \\\n    --region=us-central1\n<\/code><\/span><\/pre>\n\n\n
      \n\n\n\n
      \u2705 Step 2: Create a Cloud Router<\/h3>\n\n\n
      gcloud compute routers create nat-router \\\n    --network=default<\/span> \\\n    --region=us-central1\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
      \n\n\n\n
      \u2705 Step 3: Create the NAT Configuration<\/h3>\n\n\n
      gcloud compute routers nats create nat-config \\\n    --router=nat-router \\\n    --region=us-central1 \\\n    --nat-custom-subnet-ip-ranges=default<\/span> \\\n    --nat-external-ip-pool=nat-ip \\\n    --enable-logging\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
      Explanation:<\/h4>\n\n\n\n
        \n
      • nat-custom-subnet-ip-ranges=default<\/code> \u2192 Applies to the default subnet<\/li>\n\n\n\n
      • nat-external-ip-pool=nat-ip<\/code> \u2192 Uses the static IP created earlier<\/li>\n\n\n\n
      • --enable-logging<\/code> \u2192 Enables Cloud NAT logs<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n
        \u2705 Step 4: Test NAT Access<\/h3>\n\n\n\n
        Spin up a VM without a public IP and test:<\/p>\n\n\n
        gcloud compute instances create vm-nat-test \\\n    --subnet=default<\/span> \\\n    --no-address \\\n    --zone=us-central1-a\n\ngcloud compute ssh vm-nat-test --zone=us-central1-a\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
        Once inside:<\/p>\n\n\n
        curl https:\/\/api.ipify.org<\/span>\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
        You should get the external IP address of your NAT gateway!<\/p>\n\n\n\n
        \n\n\n\n
        \ud83d\udcca Logging and Monitoring<\/h2>\n\n\n\n
        Enable VPC flow logs and NAT logging to track:<\/p>\n\n\n\n
          \n
        • Number of connections<\/li>\n\n\n\n
        • Ports used<\/li>\n\n\n\n
        • Source and destination<\/li>\n\n\n\n
        • Bandwidth consumption<\/li>\n<\/ul>\n\n\n\n
          This is useful for compliance, debugging, and capacity planning.<\/p>\n\n\n\n
          \n\n\n\n
          \ud83d\udd01 Alternatives to Cloud NAT<\/h2>\n\n\n\n
          Service<\/th>Use When<\/th><\/tr><\/thead>
          NAT instance (manual)<\/strong><\/td>You need custom firewall\/NAT logic<\/td><\/tr>
          Cloud Proxy (IAP)<\/strong><\/td>For authenticated user access from outside<\/td><\/tr>
          VPN\/Interconnect<\/strong><\/td>For hybrid connectivity, not just internet<\/td><\/tr>
          AWS NAT Gateway<\/strong><\/td>Equivalent in AWS ecosystem<\/td><\/tr>
          Azure NAT Gateway<\/strong><\/td>Equivalent in Azure ecosystem<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          \n\n\n\n
          \u2699\ufe0f Cloud NAT vs NAT Instance<\/h2>\n\n\n\n
          Feature<\/th>Cloud NAT<\/th>NAT Instance<\/th><\/tr><\/thead>
          Managed<\/td>\u2705<\/td>\u274c<\/td><\/tr>
          Scalable<\/td>\u2705<\/td>\ud83d\udeab (manually configured)<\/td><\/tr>
          HA\/Failover<\/td>\u2705<\/td>\u274c (requires manual setup)<\/td><\/tr>
          Logging<\/td>\u2705<\/td>Manual setup needed<\/td><\/tr>
          Maintenance<\/td>None<\/td>Requires patching, scaling, monitoring<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          \n\n\n\n
          \ud83e\uddfe Real-World Example: Private GKE with NAT<\/h2>\n\n\n\n
          A company has a private GKE cluster for running microservices. To access external APIs and pull container updates:<\/p>\n\n\n\n
            \n
          • The nodes have no public IPs<\/strong><\/li>\n\n\n\n
          • Cloud NAT + Cloud Router<\/strong> is configured<\/li>\n\n\n\n
          • No exposure to internet scanners<\/li>\n\n\n\n
          • Traffic logs are enabled for audit<\/li>\n<\/ul>\n\n\n\n
            Outcome:<\/p>\n\n\n\n
              \n
            • Secure architecture<\/li>\n\n\n\n
            • Reduced operational effort<\/li>\n\n\n\n
            • Improved compliance posture<\/li>\n<\/ul>\n\n\n\n
              \n\n\n\n
              \ud83d\udcd8 Summary<\/h2>\n\n\n\n
              Capability<\/th>Cloud NAT<\/th><\/tr><\/thead>
              Enable outbound internet for private VMs<\/td>\u2705<\/td><\/tr>
              No public IPs required<\/td>\u2705<\/td><\/tr>
              Fully managed<\/td>\u2705<\/td><\/tr>
              Works with Compute Engine, GKE, Cloud Run VPC<\/td>\u2705<\/td><\/tr>
              Logging & Monitoring<\/td>\u2705<\/td><\/tr>
              Scalable & HA<\/td>\u2705<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
              \n\n\n\n
              \u2705 Conclusion<\/h2>\n\n\n\n
              Google Cloud NAT<\/strong> is an essential component for securely allowing internet access from private Google Cloud networks<\/strong>. It’s reliable, scalable, and easy to set up \u2014 making it a go-to tool in cloud-native and security-conscious environments.<\/p>\n\n\n\n
              <\/p>\n","protected":false},"excerpt":{"rendered":"
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