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AS3527 National Institutes of Health

NIH-NET - National Institutes of Health · registered in the United States

IPv4 addresses324,60863 prefixes · 0.010% of announced IPv4
Rank in United States#217largest network in US by IPv4 space, of 18,338 · 0.02% of US
Rank worldwide#766of 79,396 networks with IPv4
IPv629 x /486 prefixes
CountryUnited States18,679 ASNs registered there
Open AS3527 in ASN lookup Look up an IP in this network (128.231.0.1) All networks in United States

IPv4 prefixes

All 63 prefixes, in address order.

  • 128.231.0.0/22
  • 128.231.4.0/22
  • 128.231.8.0/21
  • 128.231.16.0/20
  • 128.231.32.0/19
  • 128.231.64.0/18
  • 128.231.128.0/18
  • 128.231.192.0/19
  • 128.231.224.0/20
  • 128.231.240.0/22
  • 128.231.244.0/23
  • 128.231.246.0/23
  • 128.231.248.0/21
  • 137.187.0.0/16
  • 156.40.0.0/19
  • 156.40.32.0/20
  • 156.40.48.0/22
  • 156.40.52.0/24
  • 156.40.54.0/23
  • 156.40.56.0/21
  • 156.40.64.0/20
  • 156.40.80.0/21
  • 156.40.88.0/22
  • 156.40.92.0/24
  • 156.40.96.0/23
  • 156.40.100.0/22
  • 156.40.104.0/21
  • 156.40.112.0/20
  • 156.40.128.0/18
  • 156.40.192.0/22
  • 156.40.196.0/24
  • 156.40.198.0/23
  • 156.40.200.0/21
  • 156.40.208.0/20
  • 156.40.224.0/20
  • 156.40.240.0/22
  • 156.40.244.0/23
  • 156.40.247.0/24
  • 156.40.248.0/21
  • 157.98.0.0/16
  • 162.99.224.0/19
  • 165.112.16.0/20
  • 165.112.36.0/22
  • 165.112.40.0/21
  • 165.112.48.0/20
  • 165.112.64.0/19
  • 165.112.96.0/20
  • 165.112.112.0/21
  • 165.112.120.0/22
  • 165.112.126.0/24
  • 165.112.128.0/21
  • 165.112.144.0/20
  • 165.112.160.0/19
  • 165.112.192.0/23
  • 165.112.196.0/22
  • 165.112.204.0/22
  • 165.112.208.0/20
  • 165.112.224.0/20
  • 165.112.240.0/21
  • 165.112.248.0/22
  • 165.112.254.0/23
  • 192.231.145.0/24
  • 192.231.146.0/23

IPv6 prefixes

All 6 prefixes.

  • 2607:f220:400::/44
  • 2607:f220:410::/48
  • 2607:f220:412::/47
  • 2607:f220:414::/46
  • 2607:f220:418::/46
  • 2607:f220:41c::/47

Other ASNs named National Institutes of Health

1 other network uses the same organisation name; together with AS3527 they announce 333,056 IPv4 addresses.

ASNNameIPv4 addresses
AS30387NIH-NET-NCCS - National Institutes of Health US8,448

Similar-sized networks in United States

ASNNameIPv4 addresses
AS68#214 LANL-NM - Los Alamos National Laboratory328,448
AS6289#215 AHM-CORP - American Honda Motor Company, Inc.328,448
AS217#216 UMN-SYSTEM - University of Minnesota325,632
AS8047#218 GCI - GENERAL COMMUNICATION, INC.324,352
AS29992#219 VA-TMP-CORE - U.S. Department of Veterans Affairs323,328
AS3477#220 NOAA-NWAVE - National Oceanic and Atmospheric Administration321,280

IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources