AS509

AS509 is a legacy Defense Network Information Center (DNIC) autonomous system registered under ARIN to the United States Department of Defense (DoD), with all administrative and technical contacts routing through DISA-Columbus in Whitehall, Ohio. ARIN's RDAP record shows a top-level autnum registration event dated 1989-08-07, making this one of the oldest ASN allocations still held in the DoD's DNIC block, with the record last changed 2025-09-12. AS509 is currently dormant in global BGP: every routing source consulted (RIPEstat, CAIDA AS Rank, bgp.he.net, bgp.tools) agrees it announces zero IPv4 and zero IPv6 prefixes today, has no visible upstreams, peers, or customer cone beyond itself, and its CAIDA AS rank of 79,459 reflects that inactivity. RIPEstat's routing-status data shows AS509 last announced a prefix on 2018-01-13 (144.102.19.0/24), while bgp.he.net dates the withdrawal to 2018-01-11 — a two-day discrepancy both sources otherwise agree places the shutdown in mid-January 2018. Historically the ASN originated three now-bogon-flagged blocks (144.102.19.0/24, 144.102.120.0/24, 144.102.125.0/24) and had one documented BGP peer, AS27065, also DoD-registered. No public abuse or security incident was found tied specifically to AS509; a superficially similar 2021 "dormant Pentagon IP space" story concerns a different ASN (AS8003) and is not applicable here.

Operator

United States Department of Defense (DoD); RIR org handle USDDD; RDAP name DNIC-AS-00509 [Confirmed] — https://rdap.arin.net/registry/autnum/509

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/509

Allocated

1989-08-07 (ARIN RDAP top-level autnum registration event — a first-party RIR fact, not an IEEE/OUI-style database artifact); last changed 2025-09-12 [Confirmed, corroborated independently by bgp.tools] — https://rdap.arin.net/registry/autnum/509, https://bgp.tools/as/509

Org status

active ARIN registration record (status: active); registrant United States Department of Defense (DoD), org handle USDDD, address 3990 E. Broad Street, Columbus, OH 43218; contacts route through DISA-Columbus, 300 North James Road, Whitehall, OH 43213

[Confirmed] — https://rdap.arin.net/registry/autnum/509

Contacts

abuse/hostmaster disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil; registrations disa.columbus.ns.mbx.arin-registrations@mail.mil [Confirmed] — https://rdap.arin.net/registry/autnum/509

Website

Unknown — no dedicated AS509 operator page identified; disa.mil homepage contains no AS509-specific content [Unknown] — https://www.disa.mil

Security/abuse context (NEUTRAL, DATED)

no AS509-specific abuse signal found as of 2026-07-10 in Spamhaus ASN-DROP, AbuseIPDB-oriented searches, or NANOG archives; the unrelated, widely-reported 2021 "dormant Pentagon IP space" story (Global Resource Systems LLC pilot) concerns a different ASN, AS8003, not AS509

Network & routing

Network type

U.S. federal government/military ASN, DNIC (Defense Network Information Center) pre-RIR-style allocation administered by DISA-Columbus; currently dormant/unannounced [Likely] — https://rdap.arin.net/registry/autnum/509, https://bgp.potaroo.net/cidr/autnums.html

Size

dormant — 0 IPv4/IPv6 prefixes and 0 addresses currently announced; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — https://stat.ripe.net/AS509, https://bgp.he.net/AS509, https://bgp.tools/as/509 (CAIDA ASRank API, fetched 2026-07-10)

Routing/peering

not currently announced; 0/327 RIS peers seeing v4, 0/321 seeing v6; CAIDA degree total 0 (customer 0, peer 0, provider 0); no PeeringDB record exists for AS509 (404) so peering policy is unpublished [Confirmed] — https://stat.ripe.net/AS509, https://www.peeringdb.com/asn/509

Historical routing

first seen announcing 2001-02-20 (144.103.0.0/16); last seen announcing 2018-01-13 per RIPEstat vs. 2018-01-11 per bgp.he.net (2-day source variance, both agree on mid-January 2018); historically originated 144.102.19.0/24, 144.102.120.0/24, 144.102.125.0/24, now flagged bogon-class by bgp.he.net

[Confirmed] — https://stat.ripe.net/AS509, https://bgp.he.net/AS509

RPKI

not assessable — no currently announced prefixes, so no ROAs to validate [Confirmed] — https://stat.ripe.net/AS509, https://bgp.tools/as/509

Notable usage / peers

historical BGP peer AS27065, also a DoD-registered ASN; no current peers observed by CAIDA [Likely] — https://bgp.he.net/AS509

Analyst note

Registered but currently unrouted DoD ASN, dormant since mid-January 2018; not to be confused with AS8003 (the 2021 "Pentagon IP addresses" story).