AS633

AS633 is a legacy autonomous system number that falls within ARIN's DNIC-ASBLK-00616-00665 block (AS616–AS665), registered to the United States Department of Defense (DoD) under registrant organization handle USDDD and administered day-to-day by DISA-Columbus, the Defense Information Systems Agency's DoD Network Information Center (DNIC). The block's top-level ARIN RDAP registration event dates to 1990-04-19, with the record last updated 2025-09-12; that date is recorded here as AS633's allocated_date because it is the first-party RIR registration fact for the autnum record, not a third-party or IEEE-style scrape. Despite the active registration status, AS633 shows zero routing footprint: RIPEstat, CAIDA AS Rank, and Hurricane Electric's BGP Toolkit all independently agree it announces no IPv4 or IPv6 prefixes, is seen by none of RIPE's 326 (v4) or 322 (v6) RIS peers, and has an empty customer cone (CAIDA rank 79,459, AS degree zero across customer/peer/provider). No PeeringDB network object exists for AS633 specifically, even though the DoD's PeeringDB organization (id 17705) lists numerous sibling ASNs. No public abuse, hijack, or NANOG/Reddit community signal was found, and it is absent from the live Spamhaus ASN-DROP feed as of 2026-07-17. The overall picture is a dormant, unused reservation inside a large legacy DoD ASN block rather than an actively operated production network.

Operator

United States Department of Defense (DoD) — registrant org handle USDDD; block administered by DISA-Columbus / DoD Network Information Center (DNIC) [Confirmed] — https://rdap.arin.net/registry/autnum/633

Country / RIR

US, ARIN [Confirmed] — RIPEstat abuse-contact-finder (authoritative_rir: arin), https://stat.ripe.net/AS633

Allocated

1990-04-19 (ARIN RDAP autnum top-level registration event for block DNIC-ASBLK-00616-00665); last changed 2025-09-12 [Confirmed, corroborated independently by ipinfo.io "Allocated Apr 19, 1990"] — https://rdap.arin.net/registry/autnum/633, https://ipinfo.io/AS633

Org status

active registration (block status "active" per ARIN RDAP); routing status inactive/unrouted [Confirmed] — https://rdap.arin.net/registry/autnum/633

Contacts

abuse/NOC — disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil, +1-844-347-2457 ext2 (handle MIL-HSTMST-ARIN); admin/technical — disa.columbus.ns.mbx.arin-registrations@mail.mil (handle REGIS10-ARIN); registrant address 3990 E. Broad Street, Columbus, OH 43218; ops address DISA-Columbus, 300 North James Road, Whitehall, OH 43213

[Confirmed] — https://rdap.arin.net/registry/autnum/633

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-17; not listed on Spamhaus ASN-DROP (live feed checked directly); no BGP hijack or NANOG/Reddit community reports found

Network & routing

Network type

U.S. federal government/military ASN within the DoD's legacy AS616-AS665 block; currently unrouted [Confirmed] — https://bgp.he.net/AS633, https://rdap.arin.net/registry/autnum/633

Size

dormant — 0 IPv4 and 0 IPv6 announced prefixes; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — https://stat.ripe.net/AS633, https://asrank.caida.org/asns/633, https://bgp.he.net/AS633

Routing/peering

NOT announced — 0/326 v4 RIS peers, 0/322 v6 RIS peers; CAIDA AS degree total 0 (customer 0, peer 0, provider 0); no PeeringDB network object for AS633 (DoD org 17705 lists sibling ASNs but not this one)

[Confirmed] — https://stat.ripe.net/AS633, https://asrank.caida.org/asns/633, https://www.peeringdb.com/org/17705

RPKI

not assessable — AS633 announces no prefixes, so there are no ROAs to validate [Confirmed] — https://stat.ripe.net/AS633

Notable usage

none identified; appears to be an unused/reserved allocation within the DoD's large legacy block rather than an active production network [Likely] — https://bgp.he.net/AS633, https://ipinfo.io/AS633

Related ASNs

AS616 (block record handle); DoD PeeringDB org 17705 also lists AS3529, AS5189, AS360, AS27081, AS126, AS650, AS325, AS749, AS303, AS725, AS654, AS147, AS769, AS3541, AS244, AS95, AS138, AS39, AS124 [Confirmed] — https://www.peeringdb.com/org/17705

Analyst note

ARIN RDAP's lookup for AS633 returns the block-level autnum record (handle AS616, DNIC-ASBLK-00616-00665) rather than a distinct AS633 sub-object; the block's top-level registration event (1990-04-19) is the first-party allocation date and is recorded per project instruction, not nulled as a "non-IEEE" or decoy artifact. bgp.tools could not be independently corroborated beyond bgp.he.net/RIPEstat/CAIDA

[Unknown for bgp.tools corroboration only] — n/a