133.51.64.42
Reputation · trust score
A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.
- Baseline (neutral) 65
- Long-established allocation (29y) +6
- Not on any threat blocklist +5
- Has a reverse-DNS (PTR) record +5
- Trust score 81 / 100
Experimental · trust-vectors model v1.2.0 — a transparent heuristic, not a definitive verdict. How it works →
DNS records
- Reverse DNS (PTR)
- 13351064042.ap.cc.tsukuba.ac.jp
- Forward-confirmed (FCrDNS)
- ✗ Mismatch
- PTR TTL
- 86400 s
- Reverse DNS last checked
- 2026-09-14 22:59 UTC
- Forward DNS last checked
- 2026-09-14 22:59 UTC
Forward DNS records for 13351064042.ap.cc.tsukuba.ac.jp
| Type | Value | Priority | TTL |
|---|---|---|---|
| A | 133.51.64.42 | — | 600s |
Reverse & forward DNS collected by the WorldIP scanner fleet — FCrDNS confirms the PTR hostname resolves back to this IP.
Network Allocation for 133.51.64.42
- CIDR range
- 133.51.64.0/20
- IP range (int)
- 2,234,728,448 — 2,234,732,543
- Prefix length
- /20
- Organization
- University of Tsukuba
- ASN
- AS37917
- ASN name
- University of Tsukuba
- Location
- Tsukuba, Ibaraki, Japan
- Coordinates
- 36.077600, 140.090200
- Accuracy radius
- 5 km
- Postal code
- 305-0821
- Regional Internet Registry
- APNIC
- Allocated
- 1997-03-01
- Data source(s)
- maxmind_city, maxmind_asn, ipinfo_lite, maxmind_country
- Last updated
- 2026-08-11 04:07:27
BGP Routing
Live BGP anomalies →Origin AS announcing the most-specific prefix that covers this IP, observed across our RIPE RIS collectors.
Frequently Asked Questions
Who owns 133.51.64.42?
133.51.64.42 is allocated to University of Tsukuba (AS37917), registered in Tsukuba, Japan.
Where is 133.51.64.42 located?
The geolocation for 133.51.64.42 maps to Tsukuba, Japan based on MaxMind GeoLite2 data. Accuracy depends on the provider and may represent the ISP's regional hub rather than the exact endpoint.
What network is 133.51.64.42 on?
133.51.64.42 belongs to the 133.51.64.0/20 network block announced by AS37917. This range contains 4,096 addresses.
Does 133.51.64.42 have a reverse DNS record?
Reverse DNS (PTR) records are resolved live when you visit this page. If a PTR record exists, it appears in the Reverse DNS field above. PTR records map IP addresses back to hostnames and are commonly used for email authentication and network diagnostics.
Neighbors
Other addresses in the same /24.
