AS391
Air Force Systems Networking
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
- Active-threat / abuse risk −12
- Government allocation +8
- Trust score 61 / 100
Experimental · trust-vectors model v1.3.0 — a transparent heuristic, not a definitive verdict. How it works →
⚠ 1 MOAS prefix — multiple origin ASNs detected
All MOAS anomalies →A previously stable prefix originated by AS391 is now also announced by another ASN (MOAS — Multiple-Origin AS), detected from our RIPE RIS collectors. Often benign (anycast, multi-homing, or a recent transfer) — but it can signal a route leak or prefix hijack, so it's worth inspecting.
| Prefix | Origin ASNs | Last detected (UTC) |
|---|---|---|
| 131.15.119.0/24 | AS56, AS391 | 2026-10-27 11:21:38 |
Top CIDR ranges
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS391 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 |
|---|---|---|
| 128.202.0.0/16 | 42,206 | 2026-10-27 11:08:33 |
| 199.31.3.0/24 | 39,299 | 2026-10-27 11:08:33 |
| 199.31.2.0/24 | 39,164 | 2026-10-27 11:08:33 |
| 199.251.155.0/24 | 38,281 | 2026-10-27 11:08:33 |
| 199.251.156.0/24 | 38,204 | 2026-10-27 11:08:33 |
| 128.236.0.0/16 | 37,694 | 2026-10-27 11:08:33 |
| 131.15.252.0/24 | 36,546 | 2026-10-27 11:08:33 |
| 131.15.136.0/24 | 36,516 | 2026-10-27 11:08:33 |
| 131.15.208.0/24 | 36,493 | 2026-10-27 11:08:33 |
| 131.15.144.0/21 | 36,490 | 2026-10-27 11:08:33 |
| 131.15.80.0/24 | 36,439 | 2026-10-27 11:08:33 |
| 131.15.98.0/23 | 36,412 | 2026-10-27 11:08:33 |
| 131.15.253.0/24 | 36,384 | 2026-10-27 11:08:33 |
| 204.34.211.0/24 | 36,033 | 2026-10-27 11:08:33 |
| 137.0.0.0/16 | 35,631 | 2026-10-27 11:08:33 |
| 143.141.96.0/22 | 35,542 | 2026-10-27 11:08:33 |
| 137.11.0.0/16 | 35,446 | 2026-10-27 11:08:33 |
| 206.39.58.0/24 | 33,298 | 2026-10-27 11:08:33 |
| 207.133.189.0/24 | 32,950 | 2026-10-27 11:08:33 |
| 207.133.179.0/24 | 32,925 | 2026-10-27 11:08:33 |
| 206.39.56.0/24 | 32,917 | 2026-10-27 11:08:33 |
| 131.15.234.0/24 | 31,082 | 2026-10-27 11:08:33 |
| 131.15.235.0/24 | 31,013 | 2026-10-27 11:08:33 |
| 131.15.233.0/24 | 30,950 | 2026-10-27 11:08:33 |
| 131.15.238.0/24 | 30,943 | 2026-10-27 11:08:33 |
| 131.15.237.0/24 | 30,918 | 2026-10-27 11:08:33 |
| 131.15.236.0/24 | 30,914 | 2026-10-27 11:08:33 |
| 131.15.239.0/24 | 30,675 | 2026-10-27 11:08:33 |
| 131.15.48.0/20 | 30,664 | 2026-10-27 11:08:33 |
| 131.15.64.0/20 | 30,612 | 2026-10-27 11:08:33 |
| 131.15.90.0/23 | 30,536 | 2026-10-27 11:08:33 |
| 131.15.40.0/21 | 30,532 | 2026-10-27 11:08:33 |
| 131.15.92.0/24 | 30,511 | 2026-10-27 11:08:33 |
| 131.15.38.0/23 | 30,472 | 2026-10-27 11:08:33 |
| 131.15.160.0/21 | 29,100 | 2026-10-27 11:08:33 |
| 131.15.120.0/24 | 28,925 | 2026-10-27 11:08:33 |
| 131.15.88.0/24 | 28,415 | 2026-10-27 11:08:33 |
| 131.15.119.0/24 | 16,604 | 2026-10-27 04:42:18 |
| 131.15.16.0/20 | 12,490 | 2026-09-15 15:03:32 |
| 131.15.32.0/22 | 12,473 | 2026-09-15 15:03:32 |
| 131.15.116.0/23 | 12,432 | 2026-09-15 13:41:38 |
| 132.35.120.0/24 | 7,031 | 2026-10-22 20:37:58 |
| 132.35.0.0/16 | 7,021 | 2026-10-22 20:37:58 |
| 132.50.48.0/21 | 6,990 | 2026-10-21 17:11:53 |
| 132.50.58.0/24 | 6,909 | 2026-10-21 17:11:53 |
| 132.50.56.0/24 | 6,906 | 2026-10-21 17:11:53 |
| 132.50.57.0/24 | 6,905 | 2026-10-21 17:11:53 |
| 132.50.46.0/24 | 6,831 | 2026-10-21 17:11:53 |
| 132.39.32.0/20 | 6,435 | 2026-10-21 17:11:53 |
| 132.50.47.0/24 | 6,330 | 2026-10-21 17:11:53 |
Showing top 50 of 365 announced prefixes by sample volume.
Frequently Asked Questions
What is AS391?
AS391 is an Autonomous System Number assigned to Air Force Systems Networking. 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 AS391 announce?
AS391 announces 283.6K IPv4 addresses distributed across 40 routed CIDR prefixes. The network is registered in United States.
Who operates AS391?
AS391 is operated by Air Force Systems Networking. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.
What country is AS391 registered in?
AS391 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
