AS27138
United States Department of Defense (DoD)
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 v1.2.0 — a transparent heuristic, not a definitive verdict. How it works →
About High Performance Computing Modernization Program
The United States Department of Defense High Performance Computing Modernization Program (HPCMP) was initiated in 1992 in response to Congressional direction to modernize the Department of Defense (DoD) laboratories’ high performance computing capabilities. The HPCMP provides supercomputers, a national research network, high-end software tools, a secure environment, and computational science experts that together enable the Defense laboratories and test centers to conduct research, development, test and technology evaluation activities.
⚠ 19 MOAS prefixes — multiple origin ASNs detected
All MOAS anomalies →A previously stable prefix originated by AS27138 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) |
|---|---|---|
| 205.61.254.0/23 | AS27138, AS27139 | 2026-09-13 10:41:12 |
| 205.58.106.0/24 | AS27137, AS27138 | 2026-09-13 09:11:11 |
| 205.58.105.0/24 | AS27137, AS27138 | 2026-09-13 09:11:11 |
| 128.26.94.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 198.218.8.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 198.218.26.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 128.26.96.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 128.26.38.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 128.26.97.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 198.218.175.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 198.218.20.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 198.218.5.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 128.26.40.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 128.26.37.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
| 198.218.21.0/24 | AS27137, AS27138 | 2026-09-13 08:26:10 |
Showing the 15 most recently detected of 19 MOAS prefixes. Many multi-origin prefixes on large networks are benign (anycast); see all MOAS anomalies.
Top CIDR ranges
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS27138 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 |
|---|---|---|
| 214.29.113.0/24 | 226,466 | 2026-09-15 05:43:19 |
| 139.241.243.0/24 | 225,566 | 2026-09-15 05:57:34 |
| 139.241.220.0/24 | 225,496 | 2026-09-15 05:57:34 |
| 128.26.91.0/24 | 225,357 | 2026-09-15 05:57:34 |
| 128.26.23.0/24 | 225,347 | 2026-09-15 05:57:34 |
| 128.26.89.0/24 | 225,296 | 2026-09-15 05:57:34 |
| 128.26.18.0/24 | 225,272 | 2026-09-15 05:57:34 |
| 128.26.234.0/24 | 225,239 | 2026-09-15 05:57:34 |
| 128.26.250.0/24 | 225,159 | 2026-09-15 05:57:34 |
| 128.26.22.0/24 | 225,124 | 2026-09-15 05:57:34 |
| 214.51.57.0/24 | 224,839 | 2026-09-15 05:43:11 |
| 205.60.239.0/24 | 224,289 | 2026-09-15 05:58:18 |
| 198.218.103.0/24 | 224,184 | 2026-09-15 05:58:21 |
| 198.218.39.0/24 | 224,080 | 2026-09-15 05:58:18 |
| 198.218.52.0/24 | 223,983 | 2026-09-15 05:58:18 |
| 198.220.76.0/24 | 223,940 | 2026-09-15 05:58:18 |
| 198.220.157.0/24 | 223,889 | 2026-09-15 05:58:21 |
| 198.218.80.0/24 | 223,703 | 2026-09-15 05:58:18 |
| 215.249.14.0/24 | 223,701 | 2026-09-15 05:43:11 |
| 198.220.85.0/24 | 223,607 | 2026-09-15 05:58:18 |
| 198.218.38.0/24 | 223,202 | 2026-09-15 05:58:18 |
| 214.25.211.0/24 | 223,025 | 2026-09-15 05:43:11 |
| 198.218.158.0/24 | 222,988 | 2026-09-03 10:56:27 |
| 214.25.209.0/24 | 222,914 | 2026-09-15 05:43:11 |
| 214.25.192.0/24 | 222,697 | 2026-09-15 05:43:11 |
| 214.25.193.0/24 | 222,672 | 2026-09-15 05:43:11 |
| 214.29.108.0/24 | 222,562 | 2026-09-15 05:43:11 |
| 128.26.147.0/24 | 220,906 | 2026-09-15 05:57:34 |
| 198.218.237.0/24 | 216,435 | 2026-07-15 08:09:12 |
| 214.29.124.0/24 | 141,472 | 2026-09-15 05:43:19 |
| 214.25.16.0/24 | 36,397 | 2026-09-15 05:43:11 |
| 128.26.110.0/24 | 31,523 | 2026-09-15 05:57:34 |
| 198.218.57.0/24 | 31,268 | 2026-09-15 05:58:21 |
| 198.220.153.0/24 | 30,824 | 2026-09-15 05:58:21 |
| 214.29.125.0/24 | 30,451 | 2026-09-15 05:43:11 |
| 128.26.252.0/24 | 30,212 | 2026-09-15 05:57:34 |
| 128.26.232.0/24 | 30,179 | 2026-09-15 05:57:34 |
| 128.26.137.0/24 | 30,011 | 2026-09-15 05:57:34 |
| 128.26.138.0/24 | 29,896 | 2026-09-15 05:57:34 |
| 128.26.15.0/24 | 29,872 | 2026-09-15 05:57:34 |
| 128.26.109.0/24 | 29,806 | 2026-09-15 05:57:34 |
| 128.26.21.0/24 | 29,798 | 2026-09-15 05:57:34 |
| 128.26.249.0/24 | 29,796 | 2026-09-15 05:57:34 |
| 128.26.248.0/24 | 29,793 | 2026-09-15 05:57:34 |
| 128.26.20.0/24 | 29,784 | 2026-09-15 05:57:34 |
| 128.26.243.0/24 | 29,778 | 2026-09-15 05:57:34 |
| 128.26.51.0/24 | 29,751 | 2026-09-15 05:57:34 |
| 128.26.82.0/24 | 29,750 | 2026-09-15 05:57:34 |
| 128.26.245.0/24 | 29,747 | 2026-09-15 05:57:34 |
| 128.26.48.0/24 | 29,746 | 2026-09-15 05:57:34 |
Showing top 50 of 194 announced prefixes by sample volume.
Frequently Asked Questions
What is AS27138?
AS27138 is an Autonomous System Number assigned to United States Department of Defense (DoD). 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 AS27138 announce?
AS27138 announces 47.6K IPv4 addresses distributed across 153 routed CIDR prefixes. The network is registered in United States.
Who operates AS27138?
AS27138 is operated by United States Department of Defense DoD. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.
What country is AS27138 registered in?
AS27138 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
