AS646

AS646 sits inside ARIN's DNIC-ASBLK-00616-00665 block, a 50-ASN range (AS616–AS665) registered as a single unit to the United States Department of Defense (org handle USDDD) rather than issued as an individually-named autnum object. ARIN's RDAP record for this block carries a top-level registration event dated 1990-04-19, with the record last changed 2025-09-12; that registration date is a first-party RIR fact and applies to the enclosing DNIC block covering AS646, not a per-ASN allocation. Administrative and technical contact runs through DISA-Columbus (300 North James Road, Whitehall, OH), with the registrant address on file as 3990 E. Broad Street, Columbus, OH. Operationally the ASN is dormant: every routing source checked (RIPEstat, CAIDA AS Rank, bgp.he.net) agrees on zero announced IPv4/IPv6 prefixes and zero visible BGP peers, upstreams, or customers as of mid-2026. Historical RIS data shows it last announced a route (199.10.22.0/24) on 2003-10-28, after first appearing in 2000. RDAP status remains "active" despite two decades without live announcements. No Spamhaus ASN-DROP listing or other public abuse signal was found, and the ASN is unrelated to the separately-documented 2021 DoD "dark space" BGP episode attributed to AS8003/AS749.

Operator

United States Department of Defense (DoD), ARIN org handle USDDD [Confirmed] — https://rdap.arin.net/registry/autnum/646, https://whois.arin.net/rest/org/USDDD.json

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/646

Allocated

1990-04-19 (ARIN RDAP top-level "registration" event on the DNIC-ASBLK-00616-00665 block record; NOT an IEEE date, not attributed to any per-ASN sub-record); last changed 2025-09-12 [Confirmed, corroborated by A1/A2/A3/A5] — https://rdap.arin.net/registry/autnum/646

Website

Unknown — nic.mil (the DoD NIC registration portal referenced in DoDI 8440.02) could not be reached; no confirmed public operator homepage [Unknown] — https://ipinfo.io/AS646

Security/abuse context (NEUTRAL, DATED)

not listed on the live Spamhaus ASN-DROP list as of 2026-07-17; no AS646-specific abuse, hijack, or threat-feed signal found via targeted search; distinct from the widely-covered 2021 DoD "dark IPv4 space" BGP episode, which is attributed to AS8003 and AS749, not AS646

Abuse contact

disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil

Network & routing

Network type

U.S. federal government/military ASN block; currently non-transit/dormant, not an actively operating public network [Confirmed] — https://bgp.he.net/AS646, https://ipinfo.io/AS646

Size / routing

0 announced IPv4 prefixes, 0 IPv6 prefixes, 0 address space; customer cone = singleton (1 ASN, 0 prefixes, 0 addresses); CAIDA AS rank 79459, cliqueMember false, seen false [Confirmed] — https://stat.ripe.net/AS646, https://asrank.caida.org/asns/646, https://bgp.he.net/AS646

Historical routing

first seen announcing 199.10.25.0/24 on 2000-08-18; last seen announcing 199.10.22.0/24 on 2003-10-28; unrouted since, though RDAP status remains "active" [Confirmed] — https://stat.ripe.net/AS646

Peering

0 of 326 RIS peers see it on v4, 0 of 321 on v6, 0 observed neighbours; no upstreams, peers, or IXP presence in CAIDA degree data; no published peering policy exists (not an open commercial peer) [Confirmed] — https://stat.ripe.net/AS646, https://bgp.he.net/AS646

RPKI

not assessable — no prefixes currently announced, so no ROA-to-announcement relationship to validate [Unknown] — https://stat.ripe.net/AS646

Registry object

block record DNIC-ASBLK-00616-00665 (startAutnum 616, endAutnum 665, handle AS616) covers AS646; there is no separate per-ASN autnum object [Confirmed] — https://rdap.arin.net/registry/autnum/646

Address on file

registrant 3990 E. Broad Street, Columbus, OH 43218; admin/tech facility DISA-Columbus, 300 North James Road, Whitehall, OH 43213 [Confirmed] — https://whois.arin.net/rest/org/USDDD.json

Analyst note

Legacy DoD block ASN, allocated 1990, unrouted for over two decades but formally "active" in RDAP; classified/government network profile plausibly explains the absence of any NANOG/Reddit community mentions or outage records.