AS198

AS198 is a legacy autonomous system number registered under ARIN to the United States Department of Defense (DoD), with the registrant organization handle USDDD. The number is administered through the DoD Network Information Center (DNIC) and operationally managed by the Defense Information Systems Agency (DISA) out of its Columbus, Ohio facility (DISA-Columbus). It is among the very earliest allocated ASNs — the ARIN autnum top-level registration event is dated 1988-06-02 — placing it in the first block of AS numbers handed out in the pre-commercial Internet era. The key triage point for AS198 is that it is effectively dormant today: every routing source consulted (RIPEstat, CAIDA AS Rank) agrees it announces zero IPv4 and zero IPv6 prefixes, is not visible to any of ARIN/RIS's roughly 327 IPv4 and 323 IPv6 peers, has zero observed BGP neighbours, and shows a CAIDA degree of zero across customer, peer, and provider dimensions. Its CAIDA AS rank of 79,459 and singleton customer cone (1 ASN, 0 prefixes, 0 addresses) reflect complete routing inactivity. RPKI posture cannot be assessed because there are no active originations and therefore no ROAs to validate. The DoD's live, active routing runs under numerous other ASNs (for example AS749 and the AS27064/AS27087/AS27096 ranges), not AS198. No notable public abuse signal was found as of June 2026 — AS198 does not appear in Spamhaus ASN-DROP, Feodo Tracker, FireHOL lists, or NANOG incident archives — consistent with a clean, dormant government-held ASN whose non-routing status leaves it effectively invisible to IP-reputation systems.

Operator

United States Department of Defense (DoD), registrant handle USDDD; administered by DoD Network Information Center (DNIC), operationally managed by DISA-Columbus [Confirmed] — ARIN RDAP autnum/198, whois.arin.net/rest/asn/AS198

Country / RIR

US, ARIN [Confirmed] — RIPEstat abuse-contact-finder (authoritative_rir: arin); CAIDA country.iso US

Allocated

1988-06-02 (ARIN registry date — the autnum top-level registration event; NOT an IEEE date — IEEE publishes no ASN registration dates); last changed 2025-09-12 [Confirmed] — ARIN RDAP autnum top-level events

Org status

active U.S. federal government combat support agency (DISA, formerly the Defense Communications Agency until renamed in 1991); AS198 itself is dormant, but the holding organization (DoD/DISA) is fully active [Confirmed for active org; Likely for DCA-rename detail] — en.wikipedia.org/wiki/Defense_Information_Systems_Agency

Contacts

NOC/technical/abuse disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil; ARIN-registration disa.columbus.ns.mbx.arin-registrations@mail.mil; phone +1-844-347-2457 ext 2; NOC address DISA-Columbus, 300 North James Road, Whitehall, OH 43213; registrant address 3990 E. Broad Street, Columbus, OH 43218

[Confirmed] — ARIN RDAP autnum/198, RIPEstat abuse-contact-finder

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-19 — not in Spamhaus ASN-DROP, Feodo Tracker, FireHOL lists, community ASN blacklists, or NANOG incident archives; no BGP hijack/route-leak history; non-routing status leaves zero IP-based attack surface

Network & routing

Network type

U.S. federal government / military network; AS198 is legacy/dormant. The DoD operates DISN (Defense Information Systems Network, including NIPRNet and SIPRNet); active DoD blocks route under other ASNs [Confirmed for registrant/dormancy; Likely for DISN attribution] — bgp.he.net/AS198, en.wikipedia.org/wiki/Defense_Information_Systems_Agency

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — RIPEstat routing-status / CAIDA AS Rank (2026-06)

Routing/peering

NOT announced — 0 RIS peers seeing it (0/327 v4, 0/323 v6); 0 observed neighbours; CAIDA degree total 0 (customer 0, peer 0, provider 0); no upstreams or peers visible in any source [Confirmed]. No public peering policy and no PeeringDB entry; DoD/DISN connectivity is mediated through DoD-managed boundary controls with formal connection approval rather than open peering [Confirmed for absence of policy/PeeringDB; Likely for DISN connection process] — RIPEstat routing-status, bgp.he.net/AS198, dl.dod.cyber.mil ConnProcGuide

RPKI

not assessable — AS198 announces no prefixes, so there are no ROAs to validate [Confirmed/Unknown] — RIPEstat routing-status

Notable usage

AS198 has no current routing activity. It is one of the earliest allocated ASNs (registered 1988-06-02), predating the modern commercial Internet; the DoD operates numerous other active ASNs for its DISN infrastructure [Confirmed] — bgp.he.net/AS198, db-ip.com/as198

Related ASNs

DoD operates many other ASNs (e.g. AS749, AS27064, AS27087, AS27096) carrying its active address blocks [Likely per third-party routing DBs] — bgp.he.net, db-ip.com

Analyst note

Encountered as a dormant legacy ASN registered to the U.S. Department of Defense; WHOIS resolves to DoD/DISA, but no live routing exists under AS198. Clean, inactive, early-block ASN.