Help identifying increased Networking Cloud NAT Data Processing

Google Cloud Compute Infrastructure
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1

Hi everyone,
We’ve noticed a significant increase in the “Networking Cloud NAT Data Processing” cost in our GCP billing throughout 2025.

I’d like to better understand:

  • What exactly is included in this billing item?

  • Is there a way to trace which workloads (e.g., Cloud Run, GKE, VMs, etc.) are generating this traffic?

  • Can I identify the source/destination of this NAT traffic?

  • Any recommendations to reduce these costs?

I’ve already checked the Cloud Billing Reports, but they don’t provide the level of detail I need.

Thanks in advance!

2

Hi @wagnerww2 ,

Welcome to Google Cloud Community.

Use Metrics Explorer to chart traffic data, such as request counts or bytes sent, for any Google Cloud resource. Filter by specifics like region or instance, then save the chart to a custom dashboard for continuous monitoring.

While you can identify both the source and destination of traffic transiting through your Google Cloud NAT gateway by querying and correlating the data from both VPC Flow Logs and Cloud NAT logs within Cloud Logging (Logs Explorer), you can construct a complete picture. VPC Flow Logs help you identify the internal initiator within your network, while Cloud NAT logs confirm the specific NAT IP used and provide a direct link between the internal source and the external destination, effectively allowing you to trace the journey of your NAT-ed traffic.

To investigate further on your concern you may reach out to our Google Cloud Support.

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