136.51.3.221
🏢 Ownership & Registration
| Organization | Google Fiber Inc. |
| ASN | AS16591 |
| Network Name | GFIBER-V4 |
| CIDR Block | 136.32.0.0/11 |
| RIR | ARIN |
| Country | United States |
| Abuse Contact | Available via RDAP |
🌐 DNS Intelligence
| PTR | 136-51-3-221.googlefiber.net |
| Forward Confirmed | No — PTR hostname does not resolve back to this IP (weak signal) |
| Forward Hostnames | 136-51-3-221.googlefiber.net |
🔐 DNS Hygiene
| Hygiene Score | 60% (Good) |
| SPF | Present |
| DMARC | Not configured |
| FCrDNS | Not verified |
| DNSSEC | Valid |
| CAA | Present |
☁️ Network Classification
| Infrastructure | Infrastructure / Datacenter |
| Service Purpose | Firewalled / No Services |
| Network Tier | Hosting — Infrastructure provider without advanced routing |
🔌 Services & Open Ports
| Port | Service | Protocol | Banner |
|---|---|---|---|
| No open ports detected | |||
| Server | — |
| HTTP Title | — |
🔐 TLS Certificate
| SANs | None |
| Valid From | — |
| Valid Until | — |
🛡️ Public Network Snapshot
| Origin ASN | AS16591 |
| Network Prefix | 136.51.0.0/20 |
| Route mapping | Found |
🎯 Confidence Breakdown
Per-dimension confidence scores based on source diversity and data freshness
| Dimension | Score | Sources | Observations |
|---|---|---|---|
| threat | 25% | 1 | 1 |
| routing | 25% | 1 | 1 |
| services | 25% | 1 | 1 |
| ownership | 25% | 1 | 2 |
| reputation | 0% | 0 | 0 |
| geolocation | 0% | 0 | 0 |
| Overall | 16% | 4 | 5 |
| Data Coherence | Consistent (100%) |
| Attribution | Moderate (50%) |
| OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid |
📅 Observation Timeline 🔄 Live
| First Seen | 2026-07-08 13:02:19 UTC |
| Last Seen | 2026-09-21 01:27:13 UTC |
| Profile Built | 2026-09-19 07:39:43 UTC |
| Data Freshness | Live |
| Signal Types | 15 |
| Total Observations | 19 |
Full dossier details are available via our API.
❓ Frequently Asked Questions About 136.51.3.221
Who owns the IP address 136.51.3.221?
136.51.3.221 is registered to Google Fiber Inc.. The address falls within the 136.32.0.0/11 network block. Registration is held at ARIN.
Where is 136.51.3.221 located?
Geolocation data places 136.51.3.221 in San Antonio, Texas, United States. IP geolocation is approximate and indicates the network's registered or routed location rather than a precise physical address.
Is 136.51.3.221 malicious or safe?
136.51.3.221 currently carries a low risk assessment, meaning no significant threat indicators have been observed. This assessment is generated from continuously collected signals and can change over time.
What is the hostname for 136.51.3.221?
The reverse DNS (PTR) record for 136.51.3.221 is 136-51-3-221.googlefiber.net. This hostname is not forward-confirmed, so it should be treated as a weak signal.
Is 136.51.3.221 a VPN, proxy, or data center address?
136.51.3.221 is classified as cloud infrastructure and hosting infrastructure based on network ownership and behavioural analysis.