AS504

AS504 is a legacy U.S. Department of Defense autonomous system number registered under ARIN to "Air Force Systems Networking" (ARIN OrgID 7ESG), with abuse and administrative contact routed through DISA-Columbus. ARIN does not maintain AS504 as a discrete per-ASN RDAP object; instead it resolves as part of a flattened bulk-block record spanning AS379 through AS508 (handle AS379, name AFCONC-BLOCK1-AS), a common pattern for early government ASN allocations. That block-level object's top-level registration event dates to 1989-08-04, with a last-changed event of 2008-06-06 — both first-party ARIN registry facts and both retained here rather than nulled, per the rule that RIR registration events, unlike third-party IEEE/MAC scrapes, are authoritative allocation records. Operationally, AS504 is currently dormant: RIPEstat shows zero announced IPv4 and IPv6 prefixes and zero observed BGP neighbours, with 0 of 327 v4 RIS peers and 0 of 321 v6 RIS peers seeing any announcement. CAIDA AS Rank corroborates this with rank 79,459, cliqueMember false, seen=false, and a singleton customer cone (0 prefixes, 0 addresses). No PeeringDB record exists for ASN 504, and no dedicated public operator website was found. Multiple independent research passes (ARIN RDAP, RIPEstat, CAIDA, ipinfo.io, whois.ipip.net) agree on the block attribution, the 1989 registration date, and the current unrouted status, giving this entry high overall confidence despite the ASN's dormancy.

Operator

Air Force Systems Networking (ARIN OrgID 7ESG), U.S. Air Force / DoD; part of bulk block AS379–AS508 (handle AS379, name AFCONC-BLOCK1-AS), not a discrete per-ASN registration [Confirmed] — https://rdap.arin.net/registry/autnum/504

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/504, https://stat.ripe.net/data/as-overview/data.json?resource=504

Allocated

1989-08-04 (ARIN RDAP top-level "registration" event for the containing AS379–AS508 block object; applies to AS504 as a first-party RIR registry fact, not an IEEE/third-party date); last changed 2008-06-06 [Confirmed, corroborated by three independent angles] — https://rdap.arin.net/registry/autnum/504, https://ipinfo.io/AS504, https://whois.ipip.net/AS504

Org status

active per ARIN; part of a larger Air Force ASN portfolio under the same org (7ESG), including AS416, AS425, AS486, AS499, AS502 [Confirmed] — https://rdap.arin.net/registry/autnum/504

Contacts

disa.columbus.ns.mbx.arin-registrations@mail.mil [Confirmed] — https://stat.ripe.net/data/abuse-contact-finder/data.json?resource=504

Website

Unknown — no dedicated public operator website found for AS504 or org 7ESG [Unknown]

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found via NANOG mailing-list archives or Spamhaus DROP/ASN-DROP resource pages as of 2026-07-10; absence is consistent with, but not proof beyond, the ASN's current dormancy

Network & routing

Network type

government/military infrastructure (U.S. Air Force); legacy/currently inactive, not a commercial ISP or R&E network [Confirmed] — https://rdap.arin.net/registry/autnum/504

Size / routing

unrouted — 0 IPv4 and 0 IPv6 prefixes announced; 0 of 327 v4 RIS peers and 0 of 321 v6 RIS peers see any announcement; 0 observed neighbours [Confirmed] — https://stat.ripe.net/data/routing-status/data.json?resource=504, https://stat.ripe.net/data/announced-prefixes/data.json?resource=504

CAIDA AS Rank

79459 (ARIN source); cliqueMember false; seen=false; customer cone = singleton (1 ASN, 0 prefixes, 0 addresses); asnDegree total/customer/peer/provider all 0 [Confirmed] — https://api.asrank.caida.org/v2/restful/asns/504

Peering

no PeeringDB net record found for ASN 504; no public peering policy page [Confirmed absence] — https://www.peeringdb.com/api/net?asn=504

RPKI

not assessable — AS504 announces no prefixes, so there are no ROAs to validate against; RIPEstat's rpki-validation endpoint requires a specific prefix parameter, none applicable [Unknown, honestly abstained] — https://stat.ripe.net/data/rpki-validation

Registrant address

501 East Moore Drive, Building 884, Room 1100, Gunter Annex, Maxwell AFB, AL 36114, USA [Confirmed] — https://whois.arin.net/rest/org/7ESG.html

Analyst note

Bulk-block DoD legacy allocation, currently unrouted across all consulted sources (RIPEstat, CAIDA, ipinfo.io); the absence of an operator website, peering policy, or PeeringDB entry is expected for this class of dormant government block, not a research gap.