AS273

AS273 is a legacy, ARPANET-era autonomous system number registered under ARIN to the United States Department of Defense (DoD), with org handle USDDD and the formal ASN name DNIC-AS-00273. It is administered through the DoD Network Information Center (DNIC) and operated day-to-day by DISA-Columbus — the Defense Information Systems Agency facility at 300 North James Road, Whitehall, Ohio. The ARIN RDAP autnum top-level registration event dates the allocation to 1989-03-03, placing it among the earliest blocks of 16-bit AS numbers (IANA block 1–1876, assigned by ARIN). The ASN is actively routed: it originates two IPv4 prefixes — 155.7.192.0/19 and 155.7.216.0/24 — for roughly 8,192 unique addresses, with no IPv6 announced. Routing is highly visible (326 of 327 RIPE RIS v4 peers see it) yet topologically narrow, with a single observed BGP neighbour, consistent with a single-homed government stub network whose only upstream is another DoD-operated ASN (AS27064). The DoD NIC is notably the operator of g.root-servers.net, one of the thirteen logical Internet root name servers. No notable public abuse signal was found for AS273 as of June 2026 — it does not appear in Spamhaus ASN-DROP, FireHOL/Emerging Threats, CleanTalk, or any NANOG abuse thread; the 2021 AS8003 DoD dark-space episode is a separate, unrelated ASN.

Operator

United States Department of Defense (DoD) — DoD Network Information Center (DNIC), administered by DISA-Columbus (Defense Information Systems Agency) [Confirmed] — ARIN RDAP autnum/273, ipinfo.io/AS273

Country / RIR

US, ARIN [Confirmed] — ARIN RDAP autnum/273; RIPEstat abuse-contact-finder (authoritative_rir: arin)

Allocated

1989-03-03 (ARIN RDAP autnum top-level registration event — a first-party RIR fact, NOT an IEEE date); last changed 2025-09-12 [Confirmed] — ARIN RDAP autnum top-level events[]

Org status

U.S. federal government combat-support agency (DISA / DoD); not a commercial entity; no corporate registration applicable [Confirmed] — ARIN RDAP autnum/273

Contacts

abuse/NOC disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil; phone +1-844-347-2457 ext2; org address 3990 E. Broad Street, Columbus, OH 43218; technical/NOC at DISA-Columbus, 300 North James Road, Whitehall, OH 43213 [Confirmed] — ARIN RDAP autnum/273, RIPEstat abuse-contact-finder

Website

nic.mil (domain on record; largely archived/redirecting — active contact is via DISA) [Likely] — ip2location.com/as273, archived snapshot

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-21 — not in Spamhaus ASN-DROP, FireHOL/Emerging Threats, CleanTalk, or NANOG archives; the 2021 AS8003 DoD dark-space advertisement is a SEPARATE, unrelated ASN

Network & routing

Network type

Government / Military — single-homed stub AS, U.S. federal/military internal network under DoD [Confirmed] — ipinfo.io/AS273, ARIN RDAP autnum/273

Size

2 IPv4 prefixes (155.7.192.0/19, 155.7.216.0/24) ≈ 8,192 unique IPv4 addresses; 0 IPv6 prefixes [Confirmed] — RIPEstat announced-prefixes / routing-status (resource=273)

Routing/peering

announced=true; 326/327 RIS v4 peers see it (99.7%), 0/322 v6; 1 observed neighbour; first seen 2005-01-21 (198.220.154.0/24), last seen 2026-06-21 (155.7.216.0/24) [Confirmed] — RIPEstat as-overview / routing-status (resource=273)

Upstream

AS27064 (also U.S. DoD / DNIC-operated) [Likely] — ipinfo.io/AS273 (single-source; RIPEstat reports only the neighbour count, not its identity)

Peering policy

Unknown — no public peering policy and no PeeringDB listing for AS273; DoD/DNIC stub networks do not publish open peering policies [Unknown] — ipinfo.io/AS273, peeringdb.com

RPKI

not assessed — fetch skipped RPKI validation (no prefix supplied); status not determined from this data [Unknown]

AS rank / customer cone

Unknown — CAIDA AS Rank API returned HTTP 502 [Unknown] — api.asrank.caida.org

Notable usage

DNIC operates g.root-servers.net, one of the thirteen logical Internet root name servers (instances in Columbus OH, Stuttgart-Vaihingen DE, Naples IT, Fussa JP, Honolulu HI, San Antonio TX) [Confirmed] — disa.mil/G-Root, ipinfo.io/AS273

ARIN handle

USDDD (org/registrant); ASN handle AS273; ASN name DNIC-AS-00273 [Confirmed] — ARIN RDAP autnum/273

Analyst note

Active, narrowly-routed DoD stub ASN. Dates taken strictly from RDAP autnum top-level events[]; entity sub-record registration dates (1993/2007/2009) were correctly ignored. CAIDA was unavailable (HTTP 502), so rank/cone/upstream identity are honest Unknowns.