Sh4mefulIP Address: 209.85.128.171
IP address 209.85.128.171 is registered to Google LLC and geolocates to United States. It was observed in sh4meful's dataset on June 18, 2026. Over the observation window, it has failed DMARC alignment once, targeting one sender domain. Its reverse DNS resolves to mail-yw1-f171.google.com. Network context: this address sits within GOOGLE (Google LLC), a network sh4meful has observed producing 812 failures across 185 distinct IPs during the same window.
Failure Activity Over Time
Peak activity was observed in the week of June 15, 2026 with 1 failures recorded. Activity in the most recent 30-day window declined sharply compared with the prior period (0 vs 1 failures).
This IP has claimed to send from 1 sender domain monitored by sh4meful. Because this address belongs to Google's shared mail infrastructure, multiple claimed sender domains most likely reflect legitimate multi-tenant sending rather than a bulk spoofing operation.
This page shows DMARC authentication failure data for this IP address. Learn more about this data.
Geolocation Information
- Country:
- US United States
- Coordinates:
- 37.751, -97.822
WHOIS Information
- Network Name:
- CIDR:
209.85.128.0/17- Owner:
- Google LLC
- Org ID:
GOGL- Address:
- 1600 Amphitheatre Parkway, Mountain View, CA 94043
- Reverse DNS:
-
mail-yw1-f171.google.com
Last updated: 2/5/2026
Analysis
This IP was observed generating a single DMARC authentication failure on June 18, 2026. With only one data point, the event is better read as a single suspicious observation than a sustained campaign. Every message observed from this source failed both SPF and DKIM verification. Receiving mail providers applied a reject disposition, refusing delivery outright.
The reverse DNS record (mail-yw1-f171.google.com) confirms this is a Google mail server. Authentication failures from Google's mail infrastructure are almost always a configuration issue rather than active spoofing: the most common causes are a domain's SPF record including Google's shared sending ranges while DKIM alignment fails, or a third-party sender using Google Workspace that is not authorized by the receiving domain's policy. This is worth investigating as a misconfiguration before treating it as a spoofing incident.
Geolocation places the host in United States, on infrastructure operated by Google LLC. Abuse-reporting channels in this jurisdiction are generally responsive, and reports to the network operator can result in timely remediation.
The address is hosted on Google LLC (GOOGLE), a major cloud provider. Authentication failures are spread across multiple IP ranges on this network, which is consistent with the scale of a large provider's customer base.
Across the wider GOOGLE network, 185 distinct IPs have been associated with 812 authentication failures over 2,080 observed messages, spanning 1 country. The failure pattern suggests a mix of abuse sources on this network.
If your domain appears in the From header of mail from this address, start with a misconfiguration investigation before assuming spoofing. Google's infrastructure is used by many legitimate senders, and auth failures here most often reflect a broken SPF include chain, a DKIM signing gap on a shared sending path, or a forwarding rule that breaks alignment. Verify that your authorized senders on Google are correctly publishing SPF and signing with DKIM before concluding the activity is malicious.
Your DMARC policy posture matters more than any IP-level response here. The enforcement action applied to this mail indicates your policy is already providing protection. Maintaining p=reject across all your domains closes the gap for attackers who manage partial alignment. Domains that remain at p=none long-term tend to be impersonated repeatedly, because the cost to the attacker of attempting is effectively zero.
Blocking this individual address has limited durability: an attacker can rotate to another address in the same /24 subnet at effectively zero cost. More durable responses include monitoring aggregate DMARC reports so new sources are visible as they emerge, tightening SPF to remove overly permissive include chains or +all mechanisms, and ensuring DKIM is signing every legitimate outbound stream so alignment failures are unambiguous. The formal abuse contact for Google LLC is listed in ARIN WHOIS records, and timely remediation is achievable through that channel.
Google, and Google Cloud Platform (GCP)
This is (part of) the GCP public cloud. Some email protection services run in GCP, but it is also an attack/spam vector.
Network Topology
This address is part of GOOGLE (Google LLC), announced from United States. 185 IPs in this network have been observed in sh4meful's dataset. This network belongs to a public cloud provider, where individual IPs often rotate quickly across tenants.
External Reputation Lookups
Look up this IP in external threat intelligence and reputation databases (opens in new tab):
Nearby IPs
The following IP addresses share the same /24 subnet as 209.85.128.171 and have appeared in sh4meful's dataset. Related activity in nearby addresses often indicates infrastructure operated by a single actor or provider.
- 209.85.128.232 — 3 failures, first seen 1 year ago, 592 days before this address.
- 209.85.128.228 — 2 failures, first seen 1 year ago, 565 days before this address.
- 209.85.128.103 — 1 failure, first seen 1 year ago, 371 days before this address.
- 209.85.128.104 — 1 failure, first seen 1 year ago, 377 days before this address.
- 209.85.128.176 — 1 failure, first seen 1 year ago, 555 days before this address.
- 209.85.128.197 — 1 failure, first seen 1 year ago, 604 days before this address.
- 209.85.128.198 — 1 failure, first seen 1 year ago, 546 days before this address.
- 209.85.128.199 — 1 failure, first seen 1 year ago, 630 days before this address.
Recommended Action
If this IP appears in your own DMARC reports, treat it as an unauthorized sender unless you have specifically verified it as a legitimate service you use. Ensure your DMARC policy is at p=quarantine or p=reject to prevent delivery of messages this IP claims to send from your domain. If you're new to DMARC, our complete guide walks through the mechanics.