AS515

AS515 is a legacy Defense Network Information Center (DNIC) autonomous system number registered under ARIN to the United States Department of Defense (registrant handle USDDD), with day-to-day registration and NOC duties handled by the Defense Information Systems Agency's Columbus, Ohio facility (DISA-Columbus). The ARIN RDAP record's top-level autnum registration event dates the allocation to 1989-08-31, placing AS515 among the early DNIC-block ASNs issued during the MILNET/ARPANET-to-Internet transition, well before ARIN itself was chartered in 1997; the record's last-changed timestamp is 2025-09-12, reflecting routine administrative maintenance rather than a re-allocation event. Multiple independent routing-data sources — RIPEstat, CAIDA AS Rank, and ipinfo.io — agree AS515 currently announces zero IPv4 and zero IPv6 prefixes and shows no BGP peers, upstreams, or downstreams, making it a registered-but-dormant government ASN rather than an actively routed network. Its CAIDA rank of 79,459 and a customer cone limited to itself (0 prefixes, 0 addresses) corroborate that dormancy. AS515 should not be confused with AS5927, the separately numbered DISA ASN under which the agency operates G-Root, one of the Internet's thirteen DNS root server systems. No public abuse, hijack, or blocklist reporting tied to AS515 was found as of 2026-07-10, consistent with an inactive network presenting no live attack surface.

Operator

United States Department of Defense (DoD), ARIN registrant handle USDDD; operational/registration point of contact is DISA-Columbus (Defense Information Systems Agency) [Confirmed] — https://rdap.arin.net/registry/autnum/515

Country / RIR

US, ARIN (DNIC allocation) [Confirmed] — https://rdap.arin.net/registry/autnum/515, RIPEstat abuse-contact-finder (authoritative_rir: arin)

Allocated

1989-08-31 (ARIN RDAP top-level autnum registration event, a first-party RIR fact); last changed 2025-09-12 [Confirmed — corroborated independently by two research angles reading the top-level events[]] — https://rdap.arin.net/registry/autnum/515

Org status

ARIN registration status "Active" (last changed 2025-09-12) — a registry/administrative status, distinct from ipinfo.io's "Inactive" characterization, which reflects current routing visibility (0 prefixes/peers) rather than registry standing; both recorded since they answer different questions

[Confirmed] — https://rdap.arin.net/registry/autnum/515, https://ipinfo.io/AS515

Contacts

disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil (abuse/NOC); disa.columbus.ns.mbx.arin-registrations@mail.mil (registration); DISA-Columbus, 300 North James Road, Whitehall, OH 43213, US [Confirmed] — https://rdap.arin.net/registry/autnum/515

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-10 — not in Spamhaus ASN-DROP program materials, NANOG-adjacent search results, or general threat-intel searches; consistent with a dormant ASN presenting no live attack surface [Likely — sourced absence, not a direct row-by-row parse of Spamhaus's live list] — https://www.spamhaus.org/drop/asndrop.txt

Network & routing

Network type

legacy U.S. federal/military DNIC-block ASN dating to the MILNET/ARPANET era; not a commercial ISP or transit provider [Confirmed] — https://rdap.arin.net/registry/autnum/515, https://ipinfo.io/AS515

Size/routing

dormant — 0 IPv4 and 0 IPv6 prefixes announced; 0 RIS peers seeing it (0/327 v4, 0/321 v6); CAIDA degree total 0 (customer 0, peer 0, provider 0); customer cone = 1 ASN (itself), 0 prefixes, 0 addresses

[Confirmed] — https://stat.ripe.net/AS515, https://asrank.caida.org/asns/515, https://ipinfo.io/AS515

Peering policy

not publicly published for AS515 specifically; DISA's DISN Connection Process Guide describes a gated model where NIPRNet traffic transits controlled DISN Internet Access Points, consistent with a closed, non-open-peering posture

[Likely, inferred] — https://dl.dod.cyber.mil/wp-content/uploads/connect/CPG/ConnProcGuide.html

RPKI

not evaluable — AS515 announces no prefixes, so there are no ROAs to validate against [Unknown/Not applicable] — https://stat.ripe.net/AS515 (rpki-validation requires --prefix)

Notable usage

none observed for AS515 itself; distinct from AS5927, the separately numbered DISA ASN that operates G-Root, one of 13 Internet DNS root server systems [Confirmed] — https://ipinfo.io/AS515, https://root-servers.org/

Analyst note

registered-but-unannounced legacy DoD ASN; operational identity ties to DISA-Columbus, not to be confused with DISA's separately numbered AS5927 (G-Root). IANA Reference left blank — no RFC reference was found or invented.