AS312

AS312 is a legacy autonomous system number registered under ARIN to the United States Department of Defense (DoD). It is not an individually named ASN but one member of the contiguous DoD block DNIC-ASBLK-00306-00371 (AS306–AS371), administered by the DoD Network Information Center (DNIC) through DISA-Columbus — the Columbus, Ohio facility of the Defense Information Systems Agency. The block carries notable historical weight: ARIN's autnum record shows a top-level registration event of 1989-06-30, placing it among the earliest ASN allocations in Internet history. The key triage point for AS312 is that it is operationally dormant. Every routing source consulted (RIPEstat routing-status, RIPEstat announced-prefixes, bgp.he.net) agrees it announces zero IPv4 and zero IPv6 prefixes and is not visible to any RIS peer (0/323 v4, 0/321 v6). Historically it originated two IPv4 /24 prefixes — 199.113.183.0/24 and 214.29.246.0/24 — between 2016-01-29 and 2023-02-07, both in DoD-reserved 214.x.x.x / classified-style bogon space, with a single observed neighbour, AS3541 (also DoD). It has not been seen in the global routing table since 2023-02-08. CAIDA AS Rank was unavailable (HTTP 502), so AS rank and customer cone could not be assessed. No notable public abuse signal was found as of 2026-06-28 — not in Spamhaus ASN-DROP, CleanTalk (0% spam rate), NANOG archives, or public IOC feeds — consistent with a clean, dormant, military-internal ASN.

Operator

United States Department of Defense (DoD), administered by the DoD Network Information Center (DNIC) via DISA-Columbus (Defense Information Systems Agency) [Confirmed] — ARIN RDAP autnum/312, ipinfo.io/AS312, bgp.he.net/AS312

Country / RIR

US, ARIN [Confirmed] — ARIN RDAP autnum/312; RIPEstat abuse-contact-finder (authoritative_rir: arin)

Allocated

1989-06-30 (ARIN registry date from autnum top-level events, a first-party RIR registration fact — NOT an IEEE date); last changed 2025-09-12 [Confirmed] — ARIN RDAP autnum/312 top-level events[]

ASN block

DNIC-ASBLK-00306-00371 (AS306–AS371), block handle AS306, all allocated to the DoD [Confirmed] — ARIN RDAP autnum/312 (startAutnum 306, endAutnum 371)

Org status

active U.S. federal government agency (Department of Defense); DISA-Columbus is the registrant contact; ARIN registry record active, last updated 2025-09-12, though the network is operationally dormant [Confirmed] — ARIN RDAP autnum/312, ipinfo.io/AS312

Contacts

NOC/abuse MIL-HSTMST-ARIN — disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil — +1-844-347-2457 ext2 (DISA-Columbus, 300 North James Road, Whitehall, OH 43213); registration POC REGIS10-ARIN — disa.columbus.ns.mbx.arin-registrations@mail.mil [Confirmed] — ARIN RDAP autnum/312

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-28 — not on Spamhaus ASN-DROP, CleanTalk (1 email, 0 blacklisted, 0% spam rate), NANOG archives, ThreatFox/OTX, or BGP-incident records; inactive ASN (0 prefixes/0 IPs) presents negligible current attack surface

Network & routing

Network type

U.S. federal government military network; AS312 is legacy and operationally inactive [Confirmed] — ARIN RDAP autnum/312, bgp.he.net/AS312

Size / routing

NOT announced — 0 IPv4 prefixes and 0 IPv6 prefixes; 0 RIS peers seeing it (0/323 v4, 0/321 v6); 0 current neighbours; not in the global routing table since 2023-02-08 [Confirmed] — RIPEstat routing-status / announced-prefixes (resource=312), bgp.he.net/AS312

Peering policy

none active (AS312 announces nothing); not listed on PeeringDB; public peering not applicable for a dormant military-internal ASN [Unknown] — peeringdb.com/org/17705

RPKI

not assessable — AS312 announces no prefixes, so there are no ROAs to validate; RIPEstat skipped validation (no prefix supplied) [Unknown] — bgp.he.net/AS312

AS rank / customer cone

Unknown — CAIDA AS Rank API returned HTTP 502; no downstream customers observed in routing data [Unknown] — api.asrank.caida.org (error)

Notable usage

part of the DoD NIC-managed AS block (AS306–AS371) and one of the earliest ASN allocations (registered 1989-06-30); reserved for internal U.S. military network use; essentially dormant/reserved today [Confirmed] — bgp.he.net/AS312, ARIN RDAP autnum/312, ipinfo.io/AS312

Related ASNs

AS3541 (DoD, the only historically observed BGP neighbour); AS306–AS371 are the sibling members of the same DoD block [Confirmed] — bgp.he.net/AS312, ARIN RDAP autnum/312

Registrant

United States Department of Defense (DoD), ARIN org handle USDDD, 3990 E. Broad Street, Columbus, OH 43218, US [Confirmed] — ARIN RDAP autnum/312 registrant entity

Historical originations

2 IPv4 /24 prefixes — 199.113.183.0/24 and 214.29.246.0/24 (214.x.x.x is DoD-reserved space; both flagged bogon) — originated 2016-01-29 to 2023-02-07; 0 IPv6; single observed peer AS3541 (also DoD) [Confirmed] — bgp.he.net/AS312, RIPEstat routing-status

Analyst note

Encountered as a dormant legacy ASN within a DoD block; WHOIS/RDAP resolves cleanly to the U.S. Department of Defense via DISA-Columbus. No active routing since 2023; CAIDA unavailable so rank/cone are honestly Unknown. Clean, inactive ASN.