AS728

AS728 is a dormant, unrouted autonomous system number belonging to AFCONC-BLOCK2-AS, an ARIN block spanning AS727–AS746 that is registered to Air Force Systems Networking, a U.S. Air Force and Department of Defense network space. Every routing source checked — RIPEstat and CAIDA AS Rank — agrees it announces zero IPv4 and zero IPv6 prefixes, so there is no live traffic to characterize.

The registrant address on file is 501 East Moore Dr, Bldg 884 Rm 1100, Gunther Annex, Maxwell AFB, Alabama — the historic home of Air Force network-engineering units. That address pattern is consistent with, though not explicitly confirmed by ARIN as belonging to, the 754th Electronic Systems Group (754 ELSG), so any attribution to that specific unit stays [Likely] rather than [Confirmed].

AS728 carries no individual ARIN autnum record of its own; it sits inside the AS727–AS746 block object named AFCONC-BLOCK2-AS. The block's top-level RDAP events list only a "last changed" entry dated 2008-06-06, with no top-level "registration" eventAction — two independent research passes confirmed this by pulling the raw RDAP JSON directly, so the allocation date is recorded here as Unknown rather than guessed from entity-level contact-registration timestamps that belong to the organization and admin-contact records, not to the autnum itself.

Routing-wise, AS728 is fully dormant: 0 of 331 RIPE RIS peers see it in IPv4 and 0 of 324 in IPv6, CAIDA's customer cone is a singleton (itself, 0 prefixes, 0 addresses), and its CAIDA AS rank of 79,459 places it near the bottom of the global ranking. No PeeringDB entry, published peering policy, or operator-specific website exists for the ASN.

Operator

Air Force Systems Networking (ARIN org handle 7ESG); part of AFCONC-BLOCK2-AS block (AS727–AS746) [Confirmed] — https://rdap.arin.net/registry/autnum/728

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/728

Allocated

Unknown — the autnum's top-level RDAP events[] carries only a "last changed" entry (2008-06-06), no top-level "registration" event; entity-level registration dates (7ESG org 2008-06-05, REGIS10-ARIN contact 2009-06-24) belong to entities, not the autnum, and are not substituted

[Confirmed-absent] — https://rdap.arin.net/registry/autnum/728

Org status

Active (per ARIN autnum record) [Confirmed] — https://rdap.arin.net/registry/autnum/728

Contacts

disa.columbus.ns.mbx.arin-registrations@mail.mil; "Registration" group, DISA-Columbus, 300 North James Road, Whitehall, OH 43213; +1-844-347-2457 ext2 [Confirmed] — https://rdap.arin.net/registry/autnum/728

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-25; AbuseIPDB, Spamhaus ASN-DROP API, and Talos could not be directly queried (403/404), so this is a dated, source-limited neutral finding, corroborated by bgp.he.net and ipinfo.io both tagging the ASN inactive/unrouted

Network & routing

Network type

US federal government / Department of Defense (US Air Force) network space; non-commercial, not a public ISP [Confirmed] — https://rdap.arin.net/registry/autnum/728

Size

dormant — 0 IPv4 and 0 IPv6 prefixes announced; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — CAIDA AS Rank / RIPEstat routing-status for AS728 (2026-07)

Routing/peering

NOT announced — 0/331 RIS peers see it in v4, 0/324 in v6; CAIDA asnDegree customer/peer/provider all 0; no PeeringDB net record exists [Confirmed] — RIPEstat routing-status AS728; https://www.peeringdb.com/api/net?asn=728

RPKI

not assessable — AS728 announces no prefixes, so there are no ROAs to validate [Confirmed] — RIPEstat rpki-validation response for AS728

Notable usage

Unknown — no public documentation ties AS728 to a specific named public-facing service; likely associated with the 754th Electronic Systems Group (754 ELSG) based on registrant address, but this is inferred, not an explicit ARIN crosswalk [Likely] — https://rdap.arin.net/registry/autnum/728

Related ASNs

part of the AS727–AS746 AFCONC-BLOCK2-AS block [Confirmed] — https://rdap.arin.net/registry/autnum/728

Analyst note

Dormant/unrouted government ASN inside a US Air Force ARIN block; no individual autnum record, no website, no PeeringDB entry. WebSearch quota was exhausted mid-research on two angles, limiting further corroboration of the 754 ELSG link and additional abuse-feed cross-checks.