AS364

AS364 is a legacy autonomous system number registered under ARIN to the United States Department of Defense (DoD), organization handle USDDD. ARIN serves it as part of a flat DNIC allocation block, DNIC-ASBLK-00306-00371, spanning AS306 through AS371 — a range historically reserved for U.S. defense use. Day-to-day network operations for the block sit with the Defense Information Systems Agency (DISA), the DoD combat-support agency that centrally manages the Defense Information System Network (DISN), the enterprise transport fabric underlying DoD services such as NIPRNet. Unlike its dormant sibling ranges, AS364 is actively routed: it originates roughly a /16 of IPv4 space (about 65,536 addresses across ~10 prefixes under 55.16.0.0/16, some subnets labeled for "Headquarters, USAISC" of U.S. Army lineage) plus one IPv6 prefix, 2608:c18a:2100::/40. Routing telemetry describes a single-homed stub: CAIDA shows an AS degree of one provider, zero peers, zero customers, and a customer cone containing only itself, with near-full global visibility (seen by ~323 RIS peers on both IPv4 and IPv6). Its sole observed BGP neighbor is AS306, also a DoD block ASN. Abuse-contact of record is disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil. No notable public abuse signal was found as of 2026-07-01 in Spamhaus, general threat-intel search, or NANOG archives; one third-party tool (bgp.he.net) showed an uncorroborated "announces bogons" routing-hygiene flag that could not be verified against a second source and is not treated as a security finding.

Operator

United States Department of Defense (DoD), org handle USDDD; block operationally managed by the Defense Information Systems Agency (DISA) [Confirmed] — ARIN RDAP (rdap.arin.net/registry/autnum/364), bgp.he.net/AS364

Country / RIR

US, ARIN [Confirmed] — RIPEstat abuse-contact-finder (authoritative_rir: arin), ARIN RDAP

Allocated

1989-06-30 (ARIN RDAP autnum TOP-LEVEL registration event for the DNIC-ASBLK-00306-00371 block containing AS364 — a first-party RIR registry fact, NOT an IEEE date); last changed 2025-09-12 [Confirmed] — ARIN RDAP autnum top-level events

Org status

active. ARIN RDAP shows block status "active" with a top-level registration event dated 1989-06-30 and last-changed 2025-09-12 [Confirmed] — ARIN RDAP

Contacts

abuse disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil; registrant address DISA-Columbus, 3990 E. Broad Street / 300 North James Road, Whitehall/Columbus, OH [Confirmed for abuse via RIPEstat; Confirmed for address via RDAP] — RIPEstat abuse-contact-finder, ARIN RDAP

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-01 — not in Spamhaus, general threat-intel search, or NANOG archives (Spamhaus checker and some sources returned 403/402 to automated fetch, so this is absence-of-evidence, not a clearance). bgp.he.net showed an uncorroborated "announces bogons" flag — routing hygiene, not a confirmed abuse finding

Network & routing

Network type

U.S. government / military network — part of the Defense Information System Network (DISN); not a commercial ISP, hosting, or content network [Confirmed] — DoD Cyber Exchange (dl.dod.cyber.mil, DoDI 8010.01)

Size

actively routed — ~10 IPv4 prefixes / ~65,536 IPv4 addresses (/16 equivalent, 55.16.0.0/16) plus 1 IPv6 prefix (2608:c18a:2100::/40); customer cone = 1 ASN (itself), 10 prefixes, 65,536 addresses [Confirmed] — RIPEstat as-overview/announced-prefixes, CAIDA AS Rank (asrank.caida.org/asns/364)

Routing/peering

single-homed stub — CAIDA asnDegree total 1 (provider 1, peer 0, customer 0); RIPEstat observed_neighbours = 1; sole observed BGP neighbor is AS306 (also DoD). No open/public peering policy — DoD/DISA governs connections via the DISN Connection Process Guide (authorization/compliance, not commercial peering) [Confirmed for degree; Likely for AS306 neighbor / DCPG] — CAIDA, RIPEstat, bgp.he.net/AS364, dl.dod.cyber.mil DCPG

RPKI

not assessed — RPKI validation was skipped by the tool (requires a per-prefix ROA check with a --prefix argument); posture Unknown [Unknown] — canonical fetch (rpki-validation skipped)

Notable usage

originates DoD/Army enterprise address space (55.16.0.0/16, subnets labeled "Headquarters, USAISC"; IPv6 2608:c18a:2100::/40) as part of the DISN transport fabric. Not to be conflated with the separate 2021 AS8003 (Global Resource Systems LLC) dormant-DoD-IPv4 episode, which involved a different ASN

[Likely] — bgp.he.net/AS364, RIPEstat

Related ASNs

AS306 (sole observed BGP neighbor, also a DoD block ASN); the DNIC-ASBLK-00306-00371 block spans AS306–AS371 [Confirmed] — ARIN RDAP, bgp.he.net/AS364

Analyst note

Encountered as an actively-routed DoD block ASN. ARIN returns AS364 nested inside the DNIC flat block object (handle AS306, startAutnum 306 / endAutnum 371) — this is ARIN's standard RDAP shape for DoD/DNIC blocks, so the block-level top-level events ARE the correct autnum events for AS364. Nested entity dates (MIL-HSTMST-ARIN 1993-05-26; REGIS10-ARIN 2009-06-24; USDDD org 2007-01-12) are decoys and were excluded.