AS387

AS387 is a legacy autonomous system number administered by ARIN within a single aggregate block, AFCONC-BLOCK1-AS, that spans AS379 through AS508 and is registered to Air Force Systems Networking (ARIN organization handle 7ESG) — a U.S. Department of Defense / U.S. Air Force network entity whose registrant address is 501 East Moore Dr, Bldg 884 Rm 1100, Gunter Annex, Maxwell AFB, AL. AS387 does not have its own discrete ARIN RDAP autnum object; querying it resolves to the containing block record (handle AS379, startAutnum 379, endAutnum 508), a normal artifact of how early-1980s DoD number ranges were registered as ranges rather than as individual entries. Abuse, administrative, and technical contact routes through DISA-Columbus (300 North James Road, Whitehall, OH; disa.columbus.ns.mbx.arin-registrations@mail.mil; +1-844-347-2457 ext2), consistent with Defense Information Systems Agency administration. The key triage point is that AS387 is effectively dormant: RIPEstat reports it announces zero IPv4 and zero IPv6 prefixes, is seen by 0 of ~323 RIS peers (v4) and 0 of ~321 (v6), and has zero observed neighbours. Historical routing shows it was visible in the past (first seen prefix 143.250.0.0/16 on 2002-02-06; last seen 132.3.48.0/22 on 2019-10-31) but is not announced today. RPKI posture is not assessable because there are no active originations and therefore no ROAs. No notable public abuse or threat signal was found as of July 2026 in general threat-intel search coverage or NANOG archives — though this is a dated, search-based null, not an authoritative live Spamhaus feed query. CAIDA AS Rank could not be obtained (the lookup timed out), so AS-rank and customer-cone metrics are left Unknown rather than guessed.

Operator

Air Force Systems Networking, U.S. Department of Defense / U.S. Air Force (ARIN org handle 7ESG; registrant Maxwell AFB / Gunter Annex, AL) [Confirmed] — ARIN RDAP autnum top-level registrant entity

Country / RIR

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

Allocated

1989-08-04 (ARIN RDAP autnum TOP-LEVEL registration event for the AFCONC-BLOCK1-AS block that contains AS387 — a first-party RIR registry fact, not an IEEE/OUI scrape); block record last changed 2008-06-06 [Confirmed] — https://rdap.arin.net/registry/autnum/387 (resolves to autnum/379 aggregate)

Org status

Active per ARIN RDAP (block status "active"); no indication of deallocation or transfer [Confirmed] — ARIN RDAP status[]

Contacts

DISA-Columbus registration/abuse — disa.columbus.ns.mbx.arin-registrations@mail.mil; +1-844-347-2457 ext2; 300 North James Road, Whitehall, OH 43213 [Confirmed] — ARIN RDAP entity REGIS10-ARIN

IANA reference

none applicable; not fabricated (block reported by RIPEstat as within IANA 16-bit AS Numbers registry range 1–1876, "Assigned by ARIN") [Confirmed] — RIPEstat as-overview.block

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-02 in general threat-intel search coverage (Spamhaus resource pages, abuse.ch) or NANOG archives; this is a search-based null, NOT an authoritative live Spamhaus SBL/DROP/ASN-DROP feed query

Network & routing

Network type

U.S. military (DoD/Air Force) address space, not a commercial ISP/content/transit network; AS387 is legacy and currently unrouted [Likely] — ARIN RDAP registrant context; no operator-published network-type statement located

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes announced; announced=false [Confirmed] — RIPEstat as-overview / announced-prefixes / routing-status (query window 2026-06-18 → 2026-07-02)

Routing/peering

NOT announced — 0 RIS peers seeing it (0/323 v4, 0/321 v6); 0 observed neighbours; no upstreams or peers visible [Confirmed]. No public peering policy page found for this ASN or the AFCONC-BLOCK1-AS block [Unknown]

RPKI

not assessable — AS387 announces no prefixes, so there are no ROAs to validate (RIPEstat rpki-validation skipped: no prefix supplied) [Confirmed] — RIPEstat

AS rank / customer cone

Unknown — CAIDA AS Rank lookup timed out ("operation was aborted due to timeout"); not fabricated. observed_neighbours=0 is consistent with an empty cone [Unknown] — CAIDA (errored)

Historical routing

first seen prefix 143.250.0.0/16 (origin 387) on 2002-02-06; last seen 132.3.48.0/22 on 2019-10-31; not visible since [Confirmed] — RIPEstat routing-status

Notable usage

Unknown from operator-official sources. No operator website, IR page, or self-published role description tied specifically to AS387 was located; a PeeringDB org "Air Force Systems Networking" (org/20118) exists but does NOT list AS387, so it is not treated as authoritative for this ASN

[Unknown] — https://www.peeringdb.com/org/20118 (checked, does not list AS387)

ASN

AS387 [Confirmed] — task target; registered inside ARIN block AFCONC-BLOCK1-AS (startAutnum 379 / endAutnum 508), https://rdap.arin.net/registry/autnum/387

Analyst note

AS387 has no discrete RDAP record — it is one number inside the AFCONC-BLOCK1-AS aggregate (AS379–AS508); the RDAP fields (handle AS379, links to autnum/379) reflect the containing block, not a separate AS387 object. Currently unrouted DoD legacy ASN.