AS365

AS365 is a legacy autonomous system number registered under ARIN to the United States Department of Defense (DoD). It is not issued its own per-ASN RDAP object; instead it sits inside the contiguous block DNIC-ASBLK-00306-00371 (AS306–AS371), a range the DoD Network Information Center (DNIC) holds and the Defense Information Systems Agency (DISA) administers day to day from DISA-Columbus (Whitehall, OH). Because ARIN publishes one autnum object for the whole block, the block's top-level registration event of 1989-06-30 is the authoritative first-party allocated date for AS365. Unlike the dormant AS306 lead, AS365 is actively announced: RIPEstat shows three IPv4 prefixes (55.18.0.0/16, 55.69.0.0/16, 55.69.16.0/24 — roughly 131,072 addresses) and one IPv6 prefix (2608:10b:2200::/40), all with near-full global visibility (v4 seen by 323/325 RIS peers). Third-party BGP tools tag the AS365 prefixes as "Headquarters, USAISC," suggesting a U.S. Army Information Systems Command network segment within the wider DoD block. CAIDA classifies AS365 as a stub: customer cone of one (itself), AS degree total 1 (a single provider relationship, zero peers, zero customers), consistent with an internal DoD routing member rather than an independently peering network. There is no PeeringDB record and no public peering policy; external DoD connectivity runs through DISA's DISN Connection Process. bgp.he.net's "announces bogons" flag is the known benign artifact for legacy DoD 55.0.0.0/8-family space that predates current allocation-database conventions, not a malicious-announcement signal. No notable public abuse signal was found as of 2026-07-01 in Spamhaus DROP/SBL pages, AbuseIPDB, or NANOG archives — a sourced null consistent with a legacy military stub ASN.

Operator

United States Department of Defense (DoD); administered by the Defense Information Systems Agency (DISA); block registrant handle USDDD, DISA-Columbus, Whitehall/Columbus, OH [Confirmed] — ARIN RDAP autnum, disa.mil

Country / RIR

US, ARIN [Confirmed] — ARIN RDAP autnum (rdap.arin.net/registry/autnum/365)

Allocated

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

Block context

AS365 is a member of DNIC-ASBLK-00306-00371 (AS306–AS371); ARIN issues one RDAP object for the contiguous DoD/DNIC range, so the block-level events apply to AS365 [Confirmed] — ARIN RDAP autnum

Org status

active. ARIN RDAP shows the parent block active, registrant "United States Department of Defense (DoD)," org handle USDDD, address 3990 E. Broad Street, Columbus, OH 43218; DISA is an active U.S. federal combat-support agency headquartered at Fort George G. Meade, MD

[Confirmed] — ARIN RDAP autnum, en.wikipedia.org/wiki/Defense_Information_Systems_Agency

Contacts

NOC/Abuse disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil (MIL-HSTMST-ARIN); Admin/Registrations disa.columbus.ns.mbx.arin-registrations@mail.mil (REGIS10-ARIN); both apply at the block level and thus to AS365 [Confirmed] — ARIN RDAP autnum

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-01 — not in Spamhaus DROP/SBL pages, AbuseIPDB, or NANOG archives; a legacy (1989) DoD stub ASN, structurally distinct from commercial/hosting ASNs that populate abuse feeds; DNSBL/DROP membership changes daily and was checked only at query time

Network & routing

Network type

U.S. federal government / military network on the Defense Information Systems Network (DISN); non-commercial DoD-internal routing domain, not an ISP/transit provider; AS365 prefixes tagged "Headquarters, USAISC" (Army Information Systems Command) [Confirmed for DoD/DISN; Likely for the USAISC/Army association] — bgp.he.net/AS365, bgp.tools/as/365

Size

3 IPv4 prefixes / ~131,072 addresses (55.18.0.0/16, 55.69.0.0/16, 55.69.16.0/24) + 1 IPv6 prefix (2608:10b:2200::/40) [Confirmed] — RIPEstat announced-prefixes / routing-status (queried 2026-07-01)

Routing/peering

announced with near-full visibility (v4 323/325 RIS peers; v6 322/323); CAIDA AS degree total 1 (customer 0, peer 0, provider 1); customer cone = singleton (itself); RIPEstat observed_neighbours 1; no PeeringDB record, no public peering policy [Confirmed for routing facts; Unknown for named upstream/peer identities] — RIPEstat routing-status, CAIDA ASRank

RPKI

not evaluated this run — RIPEstat rpki-validation requires a specific prefix parameter and was skipped (ASN-only query); bgp.he.net/bgp.tools reported 0 valid / 0 invalid ROAs for AS365 [Unknown for a definitive RPKI verdict; Likely no ROAs deployed] — RIPEstat rpki-validation (skipped), bgp.he.net/AS365

Notable usage

small, specific prefix set tagged "Headquarters, USAISC" — an Army network segment within the DoD block, distinct from AS306's much larger footprint; bgp.he.net "announces bogons" flag is a benign legacy-DoD-space artifact, not a malicious signal [Confirmed for prefixes; Likely for the USAISC tag and bogon-flag interpretation] — bgp.he.net/AS365, bgp.tools/as/365

Related ASNs

AS306 (lead ASN of the same DNIC block); the block spans AS306–AS371 [Confirmed] — ARIN RDAP autnum, /asn/306/

Analyst note

AS365 is a block-registered DoD/DISA member ASN. The 1989-06-30 allocated date is the block's top-level ARIN registration event (recorded, not nulled). Nested entity/POC dates (MIL-HSTMST-ARIN 1993-05-26, REGIS10-ARIN 2009-06-24, USDDD org 2007-01-12) are POC/org-record dates and were correctly excluded. Direct fetches of disa.mil/nic.mil failed this run (404/connection-refused, a tool/network-path artifact); the domains are independently well-attested official properties.