AS535

AS535 is a legacy autonomous system number registered under ARIN to "Headquarters, USAISC" — the U.S. Army Information Systems Command — and carries the DNIC-AS-00535 designation, marking it as part of the historic DoD Network Information Center block of ASNs issued to U.S. Army commands during the early ARPANET/NSFNET era. ARIN RDAP's top-level autnum record shows a registration event dated 1989-09-29, distinct from the nested entity-level dates (a 2009 update to the technical/abuse contact object and a 1990 registration on the registrant-org object) that belong to contact records rather than the ASN allocation itself. USAISC as an organization was inactivated on 1 October 1996, with its functions realigned under U.S. Army Communications-Electronics Command, yet the ARIN registration remains administratively listed as Active (last modified 2025-03-13) and is now maintained by DISA-Columbus on the registrant's behalf. Every routing source consulted — RIPEstat, CAIDA AS Rank, bgp.he.net, and bgp.tools — agrees the ASN is currently dark: zero announced IPv4 or IPv6 prefixes, zero observed BGP peers or upstreams, and a customer cone consisting solely of itself. No PeeringDB entry, public peering policy, or NANOG discussion of AS535 as a live network was found, and no abuse or blocklist signal (Spamhaus ASN-DROP) names it, consistent with a long-allocated but non-announcing government ASN held in reserve rather than an operating network.

Operator / registrant

Headquarters, USAISC (U.S. Army Information Systems Command), registrant handle HEADQU-3, Fort Huachuca, AZ 85613 [Confirmed] — https://rdap.arin.net/registry/autnum/535

Country / RIR

US, ARIN (DNIC block; IANA 16-bit AS Numbers Registry, block 1-1876, "Assigned by ARIN") [Confirmed] — https://rdap.arin.net/registry/autnum/535

Allocated

1989-09-29 — ARIN RDAP autnum TOP-LEVEL registration event (entity-level dates of 2009-06-24 on the REGIS10-ARIN contact object and 1990-03-26 on the HEADQU-3 registrant-org object are decoys tied to contact/org records, not the ASN allocation) [Confirmed] — https://rdap.arin.net/registry/autnum/535

Org status

ARIN record status Active (last modified 2025-03-13); originating command USAISC was inactivated 1 October 1996 with functions realigned to U.S. Army Communications-Electronics Command — registration now appears administratively maintained rather than operationally used [Confirmed RDAP status / Likely inactivation history] — https://rdap.arin.net/registry/autnum/535, https://www.acronymfinder.com/United-States-Army-Information-Systems-Command-(defunct;-realigned-as-a-subordinate-command-of-the-U.S.-Army-Communications_Electronics-Command-as-of-1-October-1996)-(USAISC).html

Website

none found — no dedicated public operator page names AS535 specifically [Confirmed (absence verified)] — https://rdap.arin.net/registry/autnum/535

Abuse / technical contact

REGIS10-ARIN (DISA-Columbus), 300 North James Road, Whitehall, OH 43213; disa.columbus.ns.mbx.arin-registrations@mail.mil; +1-844-347-2457 ext2

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-10 — AS535 does not appear in the live Spamhaus ASN-DROP feed, and no NANOG archive posts or BGP hijack/route-leak trackers reference it; consistent with a dormant, unrouted ASN presenting no live abuse surface

Network & routing

Network type

legacy U.S. Department of Defense / U.S. Army network (DNIC-AS-00535); government/military, not a commercial ISP [Confirmed] — https://rdap.arin.net/registry/autnum/535

Routing status

NOT announced — 0 of 325 RIS peers seeing IPv4, 0 of 322 seeing IPv6; 0 announced prefixes either family; CAIDA AS degree total 0 (customer 0, peer 0, provider 0); customer cone = 1 ASN / 0 prefixes / 0 addresses [Confirmed] — https://stat.ripe.net/AS535#tabId=routing, https://asrank.caida.org/asns/535, https://bgp.he.net/AS535, https://bgp.tools/as/535

CAIDA AS rank

79459 (asnName DNIC-AS-00535, cliqueMember false, seen false) [Confirmed] — https://asrank.caida.org/asns/535

RPKI

not assessable — no announced prefixes to validate against a ROA; RIPEstat rpki-validation requires a specific prefix and none exists for AS535 [Confirmed] — https://stat.ripe.net/AS535

Peering policy / IXP presence

none found — no PeeringDB net object exists for AS535 (404), no public peering-policy page, no observed BGP peers on bgp.he.net or bgp.tools [Confirmed (absence verified)] — https://www.peeringdb.com/api/net?asn=535, https://bgp.he.net/AS535

Related ASNs

sibling DNIC/DoD-block ASNs registered to the same Headquarters, USAISC holder family reportedly include AS13, AS153, AS252, AS672, AS1516, AS1539, AS1649, AS4010 [Likely, single-source] — https://bgp.tools/as/535

Last changed (autnum top-level)

2011-08-02 [Confirmed] — https://rdap.arin.net/registry/autnum/535

Analyst note

legacy, non-announcing DoD/Army ASN; WHOIS/RDAP resolves to Headquarters, USAISC but the originating command was inactivated in 1996 and current routing/peering data show no live network behind the allocation.