AS435

AS435 is a legacy autonomous system number registered under ARIN and held by the U.S. Department of the Air Force. It falls inside the covering block AS379–AS508, which ARIN records under the name AFCONC-BLOCK1-AS with the registrant "Air Force Systems Networking" (ARIN org handle 7ESG, Maxwell AFB, Alabama); the administrative, technical, and abuse contacts are delegated to DISA-Columbus (Whitehall, Ohio). Community sources associate the block with USAF electronic-systems/network units, but no operator record is dedicated to AS435 specifically. The decisive triage point is that AS435 is operationally dormant: every routing source agrees it announces zero IPv4 and zero IPv6 prefixes. RIPEstat as-overview reports announced: false; routing-status shows 0 of 324 IPv4 RIS peers and 0 of 320 IPv6 RIS peers seeing it, with 0 observed neighbours going back to the earliest lookback (2000-08-01). CAIDA corroborates: AS rank 79,459, a customer cone that is just itself (1 ASN, 0 prefixes, 0 addresses), seen: false, cliqueMember: false, and an AS degree of zero across customer, peer, and provider. RPKI posture is not assessable because there are no active originations and therefore no ROAs. No notable public abuse signal was found as of 2026-07-02 — nothing surfaced on Spamhaus or in NANOG archives — which is consistent with a clean, unrouted DoD legacy block.

Operator

U.S. Department of the Air Force — ARIN registrant "Air Force Systems Networking" (org handle 7ESG, Maxwell AFB, AL); block name AFCONC-BLOCK1-AS [Confirmed] — ARIN RDAP autnum/435 (returns covering block AS379–AS508)

Country / RIR

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

Allocated

1989-08-04 (ARIN RDAP autnum top-level registration event for the covering block; a first-party RIR fact, NOT an IEEE date); last changed 2008-06-06 [Confirmed] — ARIN RDAP autnum top-level events[]

Org status

active U.S. government / military allocation (block RDAP status "active"), but the ASN is operationally dormant (not announced) [Confirmed] — ARIN RDAP autnum/435, bgp.he.net/AS435

Contacts

abuse disa.columbus.ns.mbx.arin-registrations@mail.mil (DISA-Columbus, Whitehall, OH); registrant Air Force Systems Networking, Maxwell AFB, AL [Confirmed] — RIPEstat abuse-contact-finder, ARIN RDAP autnum/435

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-02 — no AS435-specific listing surfaced on Spamhaus or in NANOG archives; consistent with an unrouted government block [Likely — web search, not direct Spamhaus/NANOG tool query] — bgp.he.net/AS435, spamhaus.org

Network & routing

Network type

U.S. federal government / military legacy ARIN block allocation; not a commercial operator [Confirmed] — ARIN RDAP autnum/435

Size

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

Routing/peering

NOT announced — announced: false; 0 RIS peers seeing it (0/324 v4, 0/320 v6); CAIDA degree total 0 (customer 0, peer 0, provider 0); 0 observed neighbours; no peering policy published and no PeeringDB net record for AS435 [Confirmed] — RIPEstat as-overview / routing-status, CAIDA AS Rank

RPKI

not assessable — AS435 announces no prefixes, so there are no ROAs to validate (RIPEstat rpki-validation skipped, requires a prefix) [Confirmed] — RIPEstat rpki-validation (skipped, no --prefix)

Notable usage

registered but not actively routed on the public Internet — a reserved/dormant DoD legacy AS block; community sources tie the AFCONC block to USAF electronic-systems/network units, but no AS435-specific service is publicly documented [Confirmed for dormancy; Likely for unit attribution] — bgp.he.net/AS435, RIPEstat routing-status

Analyst note

RDAP for autnum/435 resolves to the covering block AS379–AS508 (AFCONC-BLOCK1-AS); the 1989-08-04 allocated_date is the block's top-level registration event, not the entity/POC dates (org 7ESG registration 2008-06-05; POC REGIS10-ARIN registration 2009-06-24), which are contact-record decoys. Clean, inactive ASN.