Autonomous system detail  ·  US flag US

AS49

Announced

Operated by National Institute of Standards and Technology, US flag US.

Summary

// analyst note
A federal-agency ASN tied to NIST's Gaithersburg campus; benign. The registrant is a recognized authority on BGP/RPKI security. Active-routing status inferred (confidence Medium).
// security note
NEUTRAL/DATED: no notable public abuse signal found as of 2026-06-09; clean government/research network.
IPv4 prefixes
29
~81.7K addresses
IPv6 prefixes
7
announced
Peer networks
3
3 up · 0 down
IANA block
1-1876
Assigned by ARIN
[ 01 ] — Context

About this ASN.

Updated  ·  Confidence: Medium  ·  3 sources  ·  How this page is checked

AS49 is a legacy allocation registered under ARIN to the National Institute of Standards and Technology (OrgId NIST-Z, Gaithersburg, MD), the federal standards and research agency. It is associated with the 129.6.0.0/16 Class B block (network RegDate 1987-06-12, updated 2024-09-11). The ASN appears lightly active around that block: IPinfo reports four peers, four upstreams, and 15 domains across six IPs, and NIST's own routing-research materials list "NIST (MD) AS49" as the origin for 129.6.*. Confidence is medium because an exact live prefix list was not captured. Beyond being a network operator, NIST is itself a major contributor to Internet-routing-security research — the BGP-SRx reference implementation, the NCCoE Secure Inter-Domain Routing / RPKI-ROV project documented in NIST SP 1800-14, and the NIST RPKI Monitor. The ARIN ASN RegDate is 1985-09-04 (updated 2024-09-11). A sibling, AS2648, serves NIST's Boulder, Colorado site. For triage this is a benign federal-agency ASN tied to NIST's Gaithersburg campus, whose registrant is a recognized authority on BGP/RPKI security. No notable public abuse signal was found as of June 2026.

Operator
National Institute of Standards and Technology (ARIN OrgId NIST-Z, Gaithersburg, MD 20899) [Confirmed] — ARIN RDAP
Country / RIR
US, ARIN [Confirmed]
Allocated
ARIN ASN RegDate 1985-09-04 (updated 2024-09-11; 129.6.0.0/16 network RegDate 1987-06-12) [Confirmed] — ARIN RDAP (echoed by ipgeolocation.io)
Org status
active (registry refreshed 2024)

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-09; clean government/research network — ipinfo.io

Network & routing

Network type
government (federal standards/research agency) [Confirmed]
Size
lightly active around 129.6.0.0/16; exact live prefix count not captured — IPinfo (2026-06)
Routing/peering
lightly active; IPinfo reports 4 peers, 4 upstreams, 15 domains/6 IPs; NIST slides list "NIST (MD) AS49" originating 129.6.* — IPinfo, nist.gov
Notable usage
NIST's Gaithersburg network on 129.6.0.0/16. NIST is a major Internet-routing-security research contributor (BGP-SRx, NIST SP 1800-14, RPKI Monitor) — nist.gov
Related ASNs
AS2648 (NIST Boulder, Colorado) [Confirmed]
Analyst note
A federal-agency ASN tied to NIST's Gaithersburg campus; benign. The registrant is a recognized authority on BGP/RPKI security.
[ 02 ] — Announced prefixes

What this network routes.

36 prefixes total · as observed by RouteViews at 2026-09-20 · one collector view, not a global census
// IPv4 prefixes29
  1. 129.6.128.0/17/17
  2. 129.6.64.0/18/18
  3. 129.6.64.0/19/19
  4. 129.6.96.0/20/20
  5. 129.6.0.0/21/21
  6. 129.6.120.0/21/21
  7. 129.6.16.0/21/21
  8. 129.6.40.0/21/21
  9. 129.6.56.0/21/21
  10. 129.6.116.0/22/22
  11. 129.6.24.0/22/22
  12. 129.6.32.0/22/22
  13. 129.6.52.0/22/22
  14. 129.6.8.0/22/22
  15. 129.6.114.0/23/23
  16. 129.6.12.0/23/23
  17. 129.6.38.0/23/23
  18. 129.6.48.0/23/23
  19. 129.6.113.0/24/24
  20. 129.6.14.0/24/24
  21. 129.6.15.0/24/24
  22. 129.6.28.0/24/24
  23. 129.6.29.0/24/24
  24. 129.6.30.0/24/24
  25. 129.6.31.0/24/24
  26. 129.6.36.0/24/24
  27. 129.6.50.0/24/24
  28. 132.163.96.0/24/24
  29. 132.163.97.0/24/24
// IPv6 prefixes7
  1. 2610:20:6000::/37/37
  2. 2610:20:6f15::/48/48
  3. 2610:20:6f96::/48/48
  4. 2610:20:6f97::/48/48
  5. 2610:20:6fcd::/48/48
  6. 2610:20:6fce::/48/48
  7. 2610:20:6fcf::/48/48
[ 03 ] — Notable peers & upstreams

Who it talks to.

3 observed neighbours
// Notable connections3 of 3 observed

Neighbours observed by RouteViews at 2026-09-20, lowest ASN first. Relationships are inferences from the CAIDA AS Relationships Dataset, 2026-08-01, and establish no commercial arrangement; a dash means the inference did not resolve.

ASNOperatorRole
AS3356 Level 3 Parent, LLC (Lumen Technologies) upstream
AS3477 — upstream
AS13335 Cloudflare, Inc. upstream
Neighbours observed via public BGP collectors; not a complete peering list.