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Autonomous System

AS27138

United States Department of Defense (DoD)

Announced IPs
43,008
CIDR prefixes
141
ASN
AS27138

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.

73/100
Moderate
How this score is built
  • 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 →

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.

Headquarters
Vicksburg
Summary from Wikipedia, CC BY-SA 4.0 · Data from Wikidata

Top CIDR ranges

CIDRIPsPTR DensityOrganizationCountryStateCity
128.26.16.0/21 2.0K
0.0%
United States Department of Defense DoD US
128.26.232.0/21 2.0K
0.2%
United States Department of Defense DoD US
214.51.24.0/21 2.0K
0.0%
United States Department of Defense DoD US
128.26.16.0/22 1.0K
0.0%
United States Department of Defense DoD US
128.26.20.0/22 1.0K
0.0%
United States Department of Defense DoD US
128.26.44.0/22 1.0K
0.2%
United States Department of Defense DoD US
128.26.232.0/22 1.0K
0.2%
United States Department of Defense DoD US
128.26.240.0/22 1.0K
0.0%
United States Department of Defense DoD US
128.26.16.0/23 512
0.0%
United States Department of Defense DoD US
128.26.18.0/23 512
0.0%
United States Department of Defense DoD US
128.26.20.0/23 512
0.0%
United States Department of Defense DoD US
128.26.22.0/23 512
0.0%
United States Department of Defense DoD US
128.26.24.0/23 512
0.0%
United States Department of Defense DoD US
128.26.46.0/23 512
0.2%
United States Department of Defense DoD US
128.26.82.0/23 512
0.2%
United States Department of Defense DoD US
128.26.90.0/23 512
0.0%
United States Department of Defense DoD US
128.26.100.0/23 512
0.4%
United States Department of Defense DoD US
128.26.108.0/23 512
0.4%
United States Department of Defense DoD US
128.26.144.0/23 512
0.4%
United States Department of Defense DoD US
128.26.232.0/23 512
0.2%
United States Department of Defense DoD US
128.26.244.0/23 512
0.0%
United States Department of Defense DoD US
128.26.248.0/23 512
0.2%
United States Department of Defense DoD US
128.26.252.0/23 512
0.2%
United States Department of Defense DoD US
139.241.220.0/23 512
0.0%
United States Department of Defense DoD US
139.241.242.0/23 512
0.0%
United States Department of Defense DoD US
198.218.38.0/23 512
0.2%
United States Department of Defense DoD US
198.218.40.0/23 512
0.0%
United States Department of Defense DoD US
198.218.54.0/23 512
0.0%
United States Department of Defense DoD US
198.218.56.0/23 512
0.0%
United States Department of Defense DoD US
198.218.60.0/23 512
0.0%
United States Department of Defense DoD US
198.218.70.0/23 512
0.0%
United States Department of Defense DoD US
198.218.74.0/23 512
0.0%
United States Department of Defense DoD US
198.218.80.0/23 512
0.0%
United States Department of Defense DoD US
198.218.92.0/23 512
0.0%
United States Department of Defense DoD US
198.218.118.0/23 512
0.0%
United States Department of Defense DoD US
198.218.158.0/23 512
0.0%
United States Department of Defense DoD US
198.220.76.0/23 512
0.0%
United States Department of Defense DoD US
198.220.186.0/23 512
0.4%
United States Department of Defense DoD US
198.220.190.0/23 512
0.0%
United States Department of Defense DoD US
205.60.238.0/23 512
0.0%
United States Department of Defense DoD US
205.73.190.0/23 512
1.0%
United States Department of Defense DoD US
214.25.192.0/23 512
0.0%
United States Department of Defense DoD US
214.29.116.0/23 512
1.0%
United States Department of Defense DoD US
214.29.124.0/23 512
1.8%
United States Department of Defense DoD US
128.26.15.0/24 256
0.4%
United States Department of Defense DoD US
128.26.16.0/24 256
0.0%
United States Department of Defense DoD US
128.26.19.0/24 256
0.0%
United States Department of Defense DoD US
128.26.21.0/24 256
0.0%
United States Department of Defense DoD US
128.26.39.0/24 256
0.0%
United States Department of Defense DoD US
128.26.44.0/24 256
0.4%
United States Department of Defense DoD US
128.26.45.0/24 256
0.0%
United States Department of Defense DoD US
128.26.48.0/24 256
0.8%
United States Department of Defense DoD US
128.26.51.0/24 256
0.4%
United States Department of Defense DoD US
128.26.52.0/24 256
0.4%
United States Department of Defense DoD US
128.26.58.0/24 256
0.8%
United States Department of Defense DoD US
128.26.77.0/24 256
0.0%
United States Department of Defense DoD US
128.26.79.0/24 256
0.0%
United States Department of Defense DoD US
128.26.80.0/24 256
0.4%
United States Department of Defense DoD US
128.26.82.0/24 256
0.0%
United States Department of Defense DoD US
128.26.85.0/24 256
0.4%
United States Department of Defense DoD US
128.26.87.0/24 256
0.4%
United States Department of Defense DoD US
128.26.89.0/24 256
0.0%
United States Department of Defense DoD US
128.26.91.0/24 256
0.0%
United States Department of Defense DoD US
128.26.100.0/24 256
0.4%
United States Department of Defense DoD US
128.26.102.0/24 256
0.0%
United States Department of Defense DoD US
128.26.110.0/24 256
0.4%
United States Department of Defense DoD US
128.26.116.0/24 256
0.0%
United States Department of Defense DoD US
128.26.137.0/24 256
0.0%
United States Department of Defense DoD US
128.26.138.0/24 256
0.0%
United States Department of Defense DoD US
128.26.141.0/24 256
0.0%
United States Department of Defense DoD US
128.26.147.0/24 256
0.0%
United States Department of Defense DoD US
128.26.175.0/24 256
0.0%
United States Department of Defense DoD US
128.26.231.0/24 256
0.0%
United States Department of Defense DoD US
128.26.234.0/24 256
0.4%
United States Department of Defense DoD US
128.26.239.0/24 256
0.0%
United States Department of Defense DoD US
128.26.250.0/24 256
0.0%
United States Department of Defense DoD US
139.241.220.0/24 256
0.0%
United States Department of Defense DoD US
139.241.243.0/24 256
0.0%
United States Department of Defense DoD US
198.218.1.0/24 256
0.0%
United States Department of Defense DoD US
198.218.10.0/24 256
0.4%
United States Department of Defense DoD US
198.218.15.0/24 256
0.0%
United States Department of Defense DoD US
198.218.41.0/24 256
0.0%
United States Department of Defense DoD US
198.218.49.0/24 256
0.0%
United States Department of Defense DoD US
198.218.52.0/24 256
0.0%
United States Department of Defense DoD US
198.218.54.0/24 256
0.0%
United States Department of Defense DoD US
198.218.61.0/24 256
0.0%
United States Department of Defense DoD US
198.218.73.0/24 256
0.0%
United States Department of Defense DoD US
198.218.76.0/24 256
0.0%
United States Department of Defense DoD US
198.218.79.0/24 256
0.0%
United States Department of Defense DoD US
198.218.81.0/24 256
0.0%
United States Department of Defense DoD US
198.218.83.0/24 256
0.0%
United States Department of Defense DoD US
198.218.86.0/24 256
0.0%
United States Department of Defense DoD US
198.218.91.0/24 256
0.0%
United States Department of Defense DoD US
198.218.103.0/24 256
0.4%
United States Department of Defense DoD US
198.218.112.0/24 256
0.0%
United States Department of Defense DoD US
198.218.117.0/24 256
0.0%
United States Department of Defense DoD US
198.218.157.0/24 256
0.0%
United States Department of Defense DoD US
198.218.159.0/24 256
0.0%
United States Department of Defense DoD US
198.218.162.0/24 256
0.0%
United States Department of Defense DoD US
198.218.200.0/24 256
0.0%
United States Department of Defense DoD US

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.

PrefixAnnouncement samplesLast seen
214.51.57.0/24 217,760 2026-07-23 22:00:37
205.60.239.0/24 216,939 2026-07-23 22:00:37
215.249.14.0/24 216,637 2026-07-23 22:00:37
198.218.39.0/24 216,604 2026-07-23 22:00:37
198.218.52.0/24 216,475 2026-07-23 22:00:37
198.220.76.0/24 216,467 2026-07-23 22:00:37
198.218.237.0/24 216,435 2026-07-15 08:09:12
198.218.103.0/24 216,326 2026-07-23 22:00:37
198.218.80.0/24 216,216 2026-07-23 22:00:37
139.241.243.0/24 216,216 2026-07-23 22:00:37
214.29.113.0/24 216,201 2026-07-23 21:59:57
198.218.158.0/24 216,154 2026-07-23 22:00:37
198.220.85.0/24 216,142 2026-07-23 22:00:37
139.241.220.0/24 216,134 2026-07-23 22:00:37
198.220.157.0/24 216,013 2026-07-23 22:00:37
214.25.211.0/24 215,999 2026-07-23 22:00:37
214.25.209.0/24 215,865 2026-07-23 22:00:37
198.218.38.0/24 215,728 2026-07-23 22:00:37
128.26.91.0/24 215,721 2026-07-23 22:00:37
128.26.23.0/24 215,701 2026-07-23 22:00:37
128.26.18.0/24 215,637 2026-07-23 22:00:37
214.25.192.0/24 215,625 2026-07-23 22:00:37
128.26.89.0/24 215,619 2026-07-23 22:00:37
128.26.234.0/24 215,616 2026-07-23 22:00:37
214.25.193.0/24 215,600 2026-07-23 22:00:37
128.26.250.0/24 215,518 2026-07-23 22:00:37
214.29.108.0/24 215,480 2026-07-23 22:00:37
128.26.22.0/24 215,455 2026-07-23 22:00:37
128.26.147.0/24 211,268 2026-07-23 22:00:37
214.29.124.0/24 132,795 2026-07-13 06:46:15
214.25.16.0/24 22,343 2026-07-23 22:00:40
198.218.57.0/24 20,623 2026-07-23 22:00:40
128.26.141.0/24 18,867 2026-07-23 22:00:40
198.218.250.0/24 18,794 2026-07-23 22:00:40
198.220.163.0/24 18,622 2026-07-23 22:00:47
198.219.178.0/24 18,046 2026-07-23 22:00:40
214.29.125.0/24 17,966 2026-07-13 06:46:15
128.26.175.0/24 17,632 2026-07-23 22:00:40
214.25.135.0/24 17,522 2026-07-23 22:00:40
139.241.221.0/24 17,354 2026-07-15 13:21:05
128.26.15.0/24 17,301 2026-07-23 22:00:40
214.51.24.0/21 17,248 2026-07-23 22:00:40
139.241.242.0/24 17,244 2026-07-15 13:21:05
128.26.138.0/24 17,235 2026-07-23 22:00:40
128.26.109.0/24 17,188 2026-07-23 22:00:40
205.60.237.0/24 17,185 2026-07-23 22:00:40
128.26.245.0/24 17,178 2026-07-23 22:00:40
128.26.82.0/24 17,168 2026-07-23 22:00:40
128.26.249.0/24 17,166 2026-07-23 22:00:40
128.26.248.0/24 17,156 2026-07-23 22:00:40

Showing top 50 of 186 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 43.0K IPv4 addresses distributed across 141 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.

Last updated: 2026-07-23 22:40:31 UTC
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