Sh4mefulIP Address: 2a00:1450:4864:20::12f
Dormant. IP address 2a00:1450:4864:20::12f is registered to ORG-GIL4-RIPE and geolocates to Ireland. It was observed in sh4meful's dataset on March 6, 2025. Over the observation window, it has failed DMARC alignment once, targeting one sender domain. Its reverse DNS resolves to mail-lf1-x12f.google.com. Network context: this address sits within IE-GOOGLE-20091005 (ORG-GIL4-RIPE), a network sh4meful has observed producing 37 failures across 22 distinct IPs during the same window.
Failure Activity Over Time
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:
- IE Ireland
- Coordinates:
- 53.3472, -6.2439
WHOIS Information
- Network Name:
- IE-GOOGLE-20091005
- Owner:
- ORG-GIL4-RIPE
- Reverse DNS:
-
mail-lf1-x12f.google.com
Last updated: 2/5/2026
Analysis
This IP was observed generating a single DMARC authentication failure on March 6, 2025. 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 took no enforcement action beyond reporting, indicating the sending domain's DMARC policy is set to p=none.
The reverse DNS record (mail-lf1-x12f.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 Ireland, on infrastructure operated by ORG-GIL4-RIPE. Abuse-reporting channels in this jurisdiction are generally responsive, and reports to the network operator can result in timely remediation.
The address is registered to ORG-GIL4-RIPE (IE-GOOGLE-20091005), an enterprise network operator. Concentrated authentication failures on enterprise address space can indicate either a compromised internal host being used as an unauthorized sending relay, or an organization knowingly or unknowingly operating as a spam source.
Across the wider IE-GOOGLE-20091005 network, 22 distinct IPs have been associated with 37 authentication failures over 38 observed messages, spanning 1 country. Most observed IPs on this network contribute to the failure count, suggesting the range as a whole warrants elevated scrutiny.
For IPv6 addresses, per-address blocking provides minimal protection. Cloud providers and large networks typically allocate a full /64 prefix (containing approximately 18 quintillion addresses) to each customer. An attacker assigned a /64 can rotate through effectively unlimited addresses within the same prefix at no cost. Blocking should target the /48 or /64 prefix rather than the individual address.
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. A p=none policy provides visibility but no enforcement, meaning mail is reported but not blocked. Moving to p=quarantine and then p=reject 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 ORG-GIL4-RIPE is listed in ARIN/RIPE/APNIC WHOIS records, and timely remediation is achievable through that channel.
External Reputation Lookups
Look up this IP in external threat intelligence and reputation databases (opens in new tab):
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.