BigQuery 403: IPv4 requests blocked, but IPv6 works normally

[Sergeyka]

Hi everyone,

Since March 29, 2025, all requests to BigQuery made over IPv4 (from within Dockerized Airflow 2.9.3) started failing with a 403 Forbidden error. The same service account and query logic continue to work when run locally or from environments using IPv6.

We confirmed this with:

• curl -v https://bigquery.googleapis.com from IPv4-only environment → returns 403

• curl from same host (outside container, using IPv6) → returns 404 (as expected for base URL without path)

There are no changes to service account permissions, the credentials work in all other contexts (Python SDK, gcloud CLI, local Airflow). Only Dockerized Airflow fails since the last few days — and only over IPv4

Questions:

1. Has Google Cloud started blocking requests over IPv4 from certain ranges?

2. Could this be some new restriction or security update related to VPC SC or org policies?

Any help or hints would be greatly appreciated 

Thanks!

[MJane]

Hi @Sergeyka, 

Welcome to the Google Cloud Community!

It seems that Google Cloud has not issued any announcements about blocking IPv4 requests from specific ranges. However, BigQuery and other Google Cloud services may be affected by VPC firewall rules, organization policies, or service-specific configurations that enforce IP range restrictions. It's advisable to review your organization's firewall rules or IP filtering settings for any recent modifications.

Recent updates to VPC SC include enhanced ingress and egress rules, as well as support for custom organization policies. These updates could potentially introduce new restrictions, especially if your organization has implemented stricter policies or adjusted service perimeters. 

If the issue persists, I suggest contacting Google Cloud Support as they can provide more insights to see if the behavior you've encountered is a known issue or specific to your project.

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