AS121

AS121 is a legacy summer-1987 DoD/DNIC allocation registered under ARIN to the United States Department of Defense (OrgId USDDD, managed via DISA Columbus), carrying the handle "DNIC-AS-00121." Its historical RFC-era label was "IH-POE-AS / Naval Ocean Systems Center," but the current ARIN OrgName is the generic "United States Department of Defense (DoD)" — report the 2026 registry, not the folklore. Unlike many dormant DNIC numbers, AS121 is actively announcing: per IPLocate it originates 6 IPv4 prefixes totaling roughly 9,728 addresses (no IPv6) in the 214.54.0.0 military range (e.g., 214.54.192.0/20), with "Allocated: August 13, 1987" and a registry refresh on 2025-09-12. For triage this is a live DoD network announcing military 214.x space; distinguish the current DoD holder from the historical Navy label. Upstream attribution is inconsistent across sources (IPLocate lists 0 peers; IPinfo lists 1 peer/1 upstream; a DoD upstream such as AS668 is plausible but not confirmed), so peering topology should be re-verified. No notable public abuse signal was found as of June 2026.

Operator

United States Department of Defense (DoD) (ARIN OrgId USDDD, DISA Columbus) [Confirmed] — ARIN / IPLocate. NOT Naval Ocean Systems Center (historical label).

Country / RIR

US, ARIN [Confirmed]

Allocated

"August 13, 1987" per IPLocate (Likely date); registry last updated 2025-09-12 [Likely / Confirmed update]

Org status

active

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal as of 2026-06-10; government network — iplocate.io

Network & routing

Network type

government / military (DoD) [Confirmed]

Size

6 IPv4 prefixes (~9,728 addrs), 0 IPv6 — 214.54.0.0 military range (e.g. 214.54.192.0/20) — IPLocate (2026-06)

Routing/peering

active; topology inconsistent across sources (IPLocate 0 peers; IPinfo 1 peer/1 upstream; DoD upstream e.g. AS668 plausible but unconfirmed) — re-verify; RPKI unknown — iplocate.io

Notable usage

[historical] RFC-era label "IH-POE-AS / Naval Ocean Systems Center." [current] a DoD DNIC AS announcing military 214.54.x space — defense.gov

Related ASNs

DoD DNIC family (AS94/AS95/AS96/AS115/AS118/AS124/AS126) [Likely]

Analyst note

A live DoD network announcing military 214.x space; encountered in defense-related routing. Distinguish current DoD holder from the historical Navy label. Peering topology to be reverified (sources disagree 0 vs 1 peer).