AS635

AS635 is a legacy autonomous system number administered by ARIN as part of the DNIC-ASBLK-00616-00665 block (AS616 through AS665), registered to the United States Department of Defense (DoD) and operationally managed by DISA-Columbus, the DoD Network Information Center. The containing autnum's top-level RDAP registration event dates to 1990-04-19, independently corroborated by bgp.tools' own "Registered April 19, 1990" statement — a first-party RIR fact distinct from several later entity-level "registration" timestamps (1993, 2007, 2009) attached to individual contact and organization records within the same autnum, which are administrative artifacts rather than the allocation date and were deliberately not used. AS635 historically originated up to six IPv4 /24 blocks between August 2000 and early December 2011, including Navy Network Information Center and DoD Network Information Center space, but has not appeared in the global BGP routing table since then: RIPEstat, CAIDA, bgp.he.net, and bgp.tools all independently agree it currently announces zero IPv4 and zero IPv6 prefixes, has zero observed peers or upstreams, and a customer cone consisting only of itself. The ARIN registry record remains status "active" — a registration-status field, not a routing-status field — and no public abuse, blocklist, or hijack signal was found tying AS635 to any documented incident, including the unrelated 2021 AS8003 dormant-DoD-space reactivation episode.

Operator

United States Department of Defense (DoD), Network Information Center block administered by DISA-Columbus (org handle USDDD; block handle AS616, range AS616–AS665) [Confirmed] — https://rdap.arin.net/registry/autnum/635

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/635, https://stat.ripe.net/AS635

Allocated

1990-04-19 (ARIN RDAP autnum top-level "registration" event for the containing block, corroborated by bgp.tools; distinct from entity-level registration dates of 1993-05-26, 2007-01-12, and 2009-06-24 which belong to individual contact/org records and are not used); last changed 2025-09-12

[Confirmed] — https://rdap.arin.net/registry/autnum/635, https://bgp.tools/as/635

Org status

ARIN registry status "active" for the containing block (registration-status field, last changed 2025-09-12), but operationally dormant/unrouted since December 2011 [Confirmed] — https://rdap.arin.net/registry/autnum/635

Website

no confirmed live dedicated page for AS635 or the DNIC block; DoD's general official site is disa.mil [Unknown] — https://www.disa.mil/

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-17 — not on Spamhaus ASN-DROP, not named in AbuseIPDB or general abuse-feed search, and not one of the ASNs implicated in the documented 2018 Bitcanal or 2021 AS8003 (GRS-DoD) dormant-DoD-space episodes

Network & routing

Network type

U.S. government/military; legacy DoD Network Information Center allocation, non-commercial, currently unrouted [Confirmed] — https://rdap.arin.net/registry/autnum/635, https://bgp.he.net/AS635

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes currently announced; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — https://stat.ripe.net/AS635, https://asrank.caida.org/asns/635

Routing/peering

NOT currently announced — 0/326 IPv4 and 0/321 IPv6 RIS peers seeing it; CAIDA AS degree total 0 (customer 0, peer 0, provider 0); last live announcement (198.97.97.0/24) seen 2011-12-07 per RIPEstat, with bgp.he.net independently stating "not visible since December 01, 2011" (a ~6-day cross-source discrepancy on the exact withdrawal date, presented as a range)

[Confirmed] — https://stat.ripe.net/AS635, https://bgp.he.net/AS635, https://bgp.tools/as/635

RPKI

Unknown / not assessable — RIPEstat's rpki-validation endpoint was skipped for lack of a --prefix parameter, and with zero currently-announced prefixes there is nothing live to validate ROAs against [Unknown] — https://stat.ripe.net/AS635

Notable usage

no current operational usage (unrouted since 2011); one historical BGP peer, AS27066 (also U.S. Department of Defense), observed in third-party tables, not currently live [Likely] — https://bgp.he.net/AS635

Historical announcements

up to 6 IPv4 /24 blocks first seen 2000-08-18, including Navy Network Information Center (163.251.160.0/24, 163.251.161.0/24) and DoD Network Information Center (192.231.128.0/24, 198.97.95.0/24, 198.97.97.0/24) space; one additional prefix flagged by bgp.he.net as a bogon

[Likely] — https://bgp.he.net/AS635

Registrant / contacts

United States Department of Defense (DoD), org handle USDDD, 3990 E. Broad Street, Columbus, OH 43218; NOC/technical/abuse contact MIL-HSTMST-ARIN ("Network DoD", DISA-Columbus, disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil); admin/technical contact REGIS10-ARIN ("Registration", disa.columbus.ns.mbx.arin-registrations@mail.mil)

[Confirmed] — https://rdap.arin.net/registry/autnum/635

Analyst note

registered-but-dormant DoD legacy ASN inside the DNIC-ASBLK-00616-00665 block; registry status "active" should not be conflated with routing status, which has been zero since December 2011.