AS5721
National Defense University
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
- Government allocation +8
- Trust score 73 / 100
Experimental · trust-vectors model v1.2.0 — a transparent heuristic, not a definitive verdict. How it works →
Top CIDR ranges
| CIDR | IPs | PTR Density | Organization | Country | State | City |
|---|---|---|---|---|---|---|
| 216.21.18.0/23 | 512 |
0.0%
|
National Defense University | US | Maryland | Silver Spring |
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS5721 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.
| Prefix | Announcement samples | Last seen |
|---|---|---|
| 216.21.18.0/24 | 8,300 | 2026-08-03 04:34:22 |
| 216.21.19.0/24 | 5,267 | 2026-08-03 04:37:31 |
Frequently Asked Questions
What is AS5721?
AS5721 is an Autonomous System Number assigned to National Defense University. An ASN identifies a network that controls a specific set of IP addresses and determines how traffic is routed across the internet via BGP (Border Gateway Protocol).
How many IP addresses does AS5721 announce?
AS5721 announces 512 IPv4 addresses distributed across 1 routed CIDR prefixes. The network is registered in United States.
Who operates AS5721?
AS5721 is operated by National Defense University. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.
What country is AS5721 registered in?
AS5721 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
