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CIDR
/19 · 8.2K IPs
ASN
National Institutes of Health
Reverse DNS
No PTR record
Blocklisted
Checking…
Scanning blocklists

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.

76/100
Moderate
How this score is built

Experimental · trust-vectors model v1.1.0 — a transparent heuristic, not a definitive verdict. How it works →

Network Allocation for 128.231.128.248

CIDR range
128.231.128.0/19
IP range (int)
2,162,655,232 — 2,162,663,423
Prefix length
/19
Organization
National Institutes of Health
ASN
AS3527
ASN name
National Institutes of Health
Location
Columbia, Maryland, United States
Coordinates
39.211000, -76.836200
Accuracy radius
20 km
Postal code
21045
Regional Internet Registry
ARIN
Allocated
1987-05-06
Data source(s)
maxmind_city, maxmind_asn, ipinfo_lite, maxmind_country
Last updated
2026-07-21 04:08:30

Origin AS announcing the most-specific prefix that covers this IP, observed across our RIPE RIS collectors.

Announced prefix
Origin AS
Announcement samples
3,425
Last seen
2026-07-22 22:50:56

Frequently Asked Questions

Who owns 128.231.128.248?

128.231.128.248 is allocated to National Institutes of Health (AS3527), registered in Columbia, United States.

Where is 128.231.128.248 located?

The geolocation for 128.231.128.248 maps to Columbia, United States 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 128.231.128.248 on?

128.231.128.248 belongs to the 128.231.128.0/19 network block announced by AS3527. This range contains 8,192 addresses.

Does 128.231.128.248 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.

Related

Last updated: 2026-07-22 20:57:30 UTC
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