AS305

AS305 is a legacy autonomous system number registered under ARIN to "Headquarters, USAISC" — the U.S. Army Information Systems Command, with a registrant address at Fort Huachuca, Arizona 85613. The DNIC- prefix on the ASN name marks it as a Defense Network Information Center allocation, placing it squarely inside the U.S. Department of Defense's internal network estate. Its registration date of 1989-06-27 makes it one of the earliest ASNs ever assigned, consistent with the Army's foundational presence in the ARPANET-era Internet; USAISC held a large block of contemporaneous ASNs (AS13, AS531, AS747, AS772 and others) reflecting that footprint. The key triage point for AS305 is that it is dormant today: every routing source consulted (RIPEstat as-overview, announced-prefixes, and routing-status) agrees it announces zero IPv4 and zero IPv6 prefixes, is seen by none of the ~323 IPv4 / ~321 IPv6 RIS peers, and has zero observed neighbours. RDAP still marks the ASN active and ARIN-allocated, but it is routing-inactive. USAISC was redesignated U.S. Army Signal Command in September 1996 and the Army's network mission later passed to NETCOM (est. 2002); the live technical/admin contact is now DISA Columbus (Defense Information Systems Agency, Whitehall, OH) via disa.columbus.ns.mbx.arin-registrations@mail.mil. No notable public abuse signal was found as of June 2026 — not in Spamhaus ASN-DROP, CleanTalk, URLhaus, NANOG archives, or CISA advisories — which is expected for a dormant DoD allocation with no active IP surface. RPKI posture is not assessable because the ASN originates no prefixes.

Operator

Headquarters, USAISC (U.S. Army Information Systems Command; ARIN org handle HEADQU-3, Fort Huachuca, AZ 85613) [Confirmed] — ARIN RDAP autnum/305

Country / RIR

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

Allocated

1989-06-27 (ARIN registry date from autnum top-level events 'registration', NOT an IEEE date — IEEE publishes no ASN registration dates); last changed 2011-08-24 [Confirmed] — ARIN RDAP autnum top-level events

Org status

U.S. federal military entity; original registrant USAISC inactivated/redesignated September 1996; ASN remains ARIN-allocated and active in RDAP but dormant; stewardship now under DISA Columbus, broader Army network mission under NETCOM (subordinate to U.S. Army Cyber Command, HQ Fort Huachuca AZ)

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

Block assignment

ARIN-assigned; block 1-1876 — IANA 16-bit Autonomous System Numbers Registry [Confirmed] — RIPEstat as-overview

Contacts

abuse / admin — disa.columbus.ns.mbx.arin-registrations@mail.mil (REGIS10-ARIN), +1-844-347-2457 ext. 2, 300 North James Road, Whitehall, OH 43213 [Confirmed via RIPEstat abuse-contact-finder + ARIN RDAP]

Website

none specific to AS305; successor orgs USAISEC (cecom.army.mil/USAISEC) and NETCOM (netcom.army.mil) [Confirmed] — cecom.army.mil/USAISEC, netcom.army.mil

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-28 — not in Spamhaus ASN-DROP, CleanTalk (1 email tracked, 0 blacklisted, 0% spam), URLhaus, AbuseIPDB, Cisco Talos, NANOG archives, or CISA/CERT advisories; dormant ASN with no active IP surface

Network & routing

Network type

U.S. Department of Defense / U.S. Army government network; DNIC- (Defense Network Information Center) allocation; legacy and routing-inactive [Confirmed] — bgp.tools/as/305, ARIN RDAP

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes / 0 addresses [Confirmed] — RIPEstat routing-status / announced-prefixes (2026-06)

Routing/peering

NOT announced — 0 RIS peers seeing it (0/323 v4, 0/321 v6); 0 observed neighbours; not in the global BGP table in the 2026-06-13→2026-06-27 window [Confirmed]. PeeringDB entry exists (RIR-verified 2024-11-26) but all operational fields are "Not Disclosed"; no IX presence or peering policy published

[Confirmed] — RIPEstat routing-status, peeringdb.com/asn/305

RPKI

not assessable — AS305 announces no prefixes, so RPKI validation was skipped (no prefix to validate, no ROAs) [Confirmed] — RIPEstat rpki-validation (skipped)

Notable usage

registered 1989-06-27, one of the earliest ASNs; USAISC held many contemporaneous ASNs (AS13, AS531, AS747, AS772, AS1451, AS1464, AS1637, AS1649) reflecting the Army's large early-Internet footprint; AS305 itself is now inactive (0 routes) [Confirmed] — bgp.tools/as/305, ARIN RDAP

Analyst note

Encountered as a dormant legacy DoD ASN — among the lowest-numbered, earliest-registered ASNs. WHOIS resolves to Headquarters USAISC; live admin/abuse contact is DISA Columbus. Allocated_date taken from the autnum TOP-LEVEL 'registration' event (1989-06-27); entity-level dates (HEADQU-3 org 1990-03-26, REGIS10-ARIN contact 2009-06-24) were correctly ignored as decoys. Clean, inactive ASN.