AS540

AS540 is a legacy "DNIC" (Defense Network Information Center) autonomous system registered under ARIN to the United States Department of Defense, administered day-to-day by DISA (Defense Information Systems Agency) out of DISA-Columbus in Whitehall, Ohio. The ARIN RDAP autnum object's top-level registration event places the ASN's allocation at 1989-09-29, with the object last changed on 2025-09-12. Unlike a commercial network, AS540 has no PeeringDB record (a direct API query returned no result), no public peering policy, and no dedicated operator website — DISA's public site is an agency-mission portal that does not describe AS540 specifically. Routing data is unambiguous and consistent across RIPEstat, CAIDA AS Rank, and bgp.he.net: AS540 announces zero IPv4 and zero IPv6 prefixes, has zero visible BGP peers or upstreams, zero customer-cone members beyond itself, and is not seen by any of RIPEstat's 325 (v4) or 322 (v6) RIS route-collector peers. CAIDA assigns it AS rank 79,459 with seen=false, and RPKI validation was explicitly skipped by RIPEstat because there is no announced prefix to validate against. No public abuse or threat-feed listing was found for AS540 as of 2026-07-11 across Spamhaus DROP/ASN-DROP, general ASN blocklist aggregators, or NANOG mailing-list archives, consistent with a dormant, internally-used government resource rather than an actively peered network.

Operator

United States Department of Defense (DoD), registrant handle USDDD; administered by DISA-Columbus (Network Information Center) [Confirmed] — https://rdap.arin.net/registry/autnum/540

Country / RIR

US, ARIN (DNIC allocation) [Confirmed] — https://rdap.arin.net/registry/autnum/540

Allocated

1989-09-29 — ARIN RDAP autnum TOP-LEVEL registration event (a first-party RIR fact, not an IEEE/OUI-style artifact); last changed 2025-09-12 [Confirmed, corroborated by A1 raw RDAP, A2, and A3 independently reading the same top-level events[] and excluding entity-level decoy dates] — https://rdap.arin.net/registry/autnum/540

Org status

active (RDAP status) [Confirmed] — https://rdap.arin.net/registry/autnum/540

Contacts

NOC/technical/abuse disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil; registration disa.columbus.ns.mbx.arin-registrations@mail.mil; phone +1-844-347-2457 ext2; registrant address 3990 E. Broad Street, Columbus, OH 43218; NOC address DISA-Columbus, 300 North James Road, Whitehall, OH 43213

[Confirmed] — https://rdap.arin.net/registry/autnum/540

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-11 — checked Spamhaus DROP/ASN-DROP, general ASN blocklist aggregators (bad-asn-list, ASN-BlackList), and NANOG mailing-list/meeting archives; consistent with a dormant government-numbered resource

Network & routing

Network type

not publicly disclosed; a legacy DNIC allocation used for DoD internal purposes rather than a conventional commercial transit/content network [Unknown/Likely] — https://rdap.arin.net/registry/autnum/540

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — https://stat.ripe.net/AS540, https://api.asrank.caida.org/v2/restful/asns/540

Routing/peering

NOT announced — 0 of 325 RIS peers see it over IPv4, 0 of 322 over IPv6; CAIDA asnDegree total 0 (customer 0, peer 0, provider 0); no PeeringDB record (direct query returned no result) [Confirmed] — https://stat.ripe.net/AS540, https://www.peeringdb.com/api/net?asn=540

RPKI

not assessable — RIPEstat explicitly skipped validation because AS540 has no announced prefix to validate against [Confirmed] — https://stat.ripe.net/AS540

Notable usage

Unknown/Unverified. Third-party commentary loosely associates the broader "DoD Network Information Center" ASN family with operation of G.root-servers.net, but no source ties that specifically to AS540 (as opposed to sibling DoD ASNs) [Unknown] — no citation meets sourcing bar

Related ASNs

none confirmed for AS540 specifically. Note: one third-party source (RFC 1166 / bgp.potaroo.net autnums list) attributes AS540 to "CDOIM Bamberg Information Center" in Bamberg, Germany with IP space 136.222.0.0/16 — this conflicts with the current, live ARIN RDAP registrant (US DoD / DISA-Columbus, Ohio) and is treated as a stale/historical third-party listing, not authoritative

[Unknown/conflicting, single-source] — https://bgp.potaroo.net/cidr/autnums.html, https://www.rfc-editor.org/rfc/rfc1166

Analyst note

Dormant legacy DNIC ASN registered to the U.S. DoD (via DISA-Columbus); zero BGP announcements across every routing source consulted. A single third-party historical source (RFC 1166 via bgp.potaroo.net autnums list) names a different, older custodian ("CDOIM Bamberg Information Center", Germany) — flagged as a conflicting/unverified legacy record rather than overriding the current live ARIN RDAP registrant data.