AS581

AS581 is a legacy autonomous system number registered under ARIN to "Air Force Systems Networking" (ARIN org handle 7ESG), operating under the name AMC-MAF-C2-ENCLAVES — Air Mobility Command, Mobility Air Forces, Command & Control Enclaves. The registrant's postal address places the org at Gunther Annex, Maxwell AFB, Alabama, home of the 754th Electronic Systems Group (554th Electronic Systems Wing), the unit responsible for secure combat information systems and networks across the Air Force, DoD, and partner federal agencies. Administrative and abuse contact routes through DISA-Columbus, the Defense Information Systems Agency's registration-management office in Whitehall, Ohio. ARIN's RDAP record shows a top-level autnum registration event dated 1990-02-07, independently corroborated by a third-party WHOIS aggregator citing the same ARIN-sourced date, with a last-changed event of 2012-02-07. Consistent with many DoD command-and-control ASNs, AS581 is registered but not currently visible anywhere in the global BGP routing table: zero announced IPv4 or IPv6 prefixes, zero of 325/322 RIPE RIS peers observing it, and a CAIDA customer cone limited to the ASN itself. No PeeringDB entry exists, and no current public abuse or hijack history was found, aside from an unverified, decade-old community forum mention.

Operator

Air Force Systems Networking (ARIN org handle 7ESG); registered address Gunther Annex, Maxwell AFB, AL — operationally tied to the 754th Electronic Systems Group / 554th Electronic Systems Wing [Confirmed for registrant org/address; Likely for the 754th ESG operational tie] — https://rdap.arin.net/registry/autnum/581

Country / RIR

US, ARIN [Confirmed] — https://stat.ripe.net/data/abuse-contact-finder/data.json?resource=581 (authoritative_rir: arin)

Allocated

1990-02-07 (ARIN RDAP top-level autnum registration event — NOT an IEEE date; this is a first-party RIR registration fact); last changed 2012-02-07 [Confirmed, corroborated by two independent sources] — https://rdap.arin.net/registry/autnum/581 ; https://ipgeolocation.io/browse/asn/AS581

Org status

active per ARIN RDAP status field; registrant org address 501 East Moore Dr, Bldg 884 Rm 1100, Gunther Annex, Maxwell AFB, AL 36114 [Confirmed] — https://rdap.arin.net/registry/autnum/581

Contacts

disa.columbus.ns.mbx.arin-registrations@mail.mil (DISA-Columbus, ARIN handle REGIS10-ARIN, roles abuse/administrative/technical) [Confirmed] — https://stat.ripe.net/data/abuse-contact-finder/data.json?resource=581 ; https://rdap.arin.net/registry/autnum/581

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-11 — not in Spamhaus ASN-DROP; no confirmed NANOG archive mentions in a site-restricted search. One unverified circa-2015 Reddit r/sysadmin thread referencing "Repeated DOS attacks from 754th electronic systems group" surfaced but could not be corroborated against any primary incident source, so it is not treated as a confirmed abuse finding [Unknown for the Reddit claim; Likely for the clean-record checks] — https://www.spamhaus.org/drop/asndrop.txt

Network & routing

Network type

U.S. DoD / Air Force command-and-control network enclave (AMC-MAF-C2-ENCLAVES decodes to Air Mobility Command, Mobility Air Forces, C2 Enclaves); not a commercial ISP or transit provider [Likely] — https://rdap.arin.net/registry/autnum/581

Size

dormant/unannounced — 0 IPv4 prefixes/addresses, 0 IPv6 prefixes; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — https://stat.ripe.net/data/routing-status/data.json?resource=581 ; https://asrank.caida.org/asns/581

Routing/peering

NOT announced — 0 RIS peers seeing it (0/325 v4, 0/322 v6); CAIDA AS-degree total 0 (customer 0, peer 0, provider 0); no PeeringDB entry (peeringdb.com/asn/581 returns HTTP 404) [Confirmed] — https://stat.ripe.net/data/routing-status/data.json?resource=581 ; https://asrank.caida.org/asns/581 ; https://www.peeringdb.com/asn/581

RPKI

not assessable — AS581 announces no prefixes, so RIPEstat's rpki-validation check was skipped (it requires a prefix) and there are no ROAs to evaluate [Confirmed] — https://stat.ripe.net/AS581

Notable usage

registrant org and address tie the ASN to the 754th Electronic Systems Group at Gunther Annex, Maxwell AFB, the unit that supports secure combat information systems and networks for the Air Force, DoD, and other federal agencies [Likely] — https://rdap.arin.net/registry/autnum/581

Related ASNs

none confirmed via routing data (CAIDA customer cone = the ASN itself only); DISA-Columbus (ARIN handle REGIS10-ARIN) administers the abuse/admin/tech POC and likely covers other DoD ASNs, but no specific related-ASN list was verified [Unknown] — https://rdap.arin.net/registry/autnum/581

Analyst note

closed, unannounced DoD/Air Force C2 ASN. No dedicated operator website exists for AS581 itself; the closest official parent web presence, amc.af.mil, returned HTTP 403 to automated fetch and could not be directly quoted, so background on Air Mobility Command's mission is treated as background context rather than a cited claim.