AS325

AS325 is a legacy autonomous system number registered under ARIN to the United States Department of Defense (DoD), org handle USDDD, and administered operationally by the Defense Information Systems Agency (DISA) out of Columbus, Ohio. It is not an independently registered ASN but one member of the DoD DNIC block DNIC-ASBLK-00306-00371, which spans AS306 through AS371 — a contiguous range of 66 military-managed numbers held under a single ARIN autnum record (handle AS306). The block carries a first-party ARIN registration date of 1989-06-30, one of the early legacy ARIN allocations, and was last changed 2025-09-12. AS325's announced prefixes sit inside the 55.0.0.0/8 DoD address space, primarily the aggregates 55.43.0.0/16 and 55.191.0.0/16, with reverse-DNS and registry descriptions consistently labeled "Headquarters, USAISC" — the former U.S. Army Information Systems Command, now folded into Army NETCOM. The triage point for AS325 is its current routing state: RIPEstat's as-overview reports announced=false and routing-status shows zero active IPv4 and IPv6 prefixes as of 2026-06-28, even though 35 IPv4 and 2 IPv6 prefixes were broadly visible in the global table (324/326 v4 RIS peers, 100% v6) through their last-seen timestamp of 2026-06-26. This brief withdrawal or pause sits against an otherwise clean record. The single observed BGP neighbour is an intra-DoD relationship (AS306), and no public peering policy, operator website, or IXP presence exists. No notable public abuse signal was found as of 2026-06-28 — not in Spamhaus ASN-DROP, CleanTalk, AbuseIPDB's ASN view, community bad-ASN lists, or NANOG/seclists archives — consistent with a clean, internally managed military network. The one routing-layer note is that bgp.he.net flags the network as announcing bogons, reflecting absent RPKI/bogon filtering rather than any active malicious behavior.

Operator

United States Department of Defense (DoD); ARIN org handle USDDD; administered by DISA-Columbus (Defense Information Systems Agency), Whitehall/Columbus, OH [Confirmed] — ARIN RDAP autnum/325 (resolves to block handle AS306), bgp.tools/as/325

Country / RIR

US, ARIN [Confirmed] — ARIN RDAP autnum/325; corroborated by RIPEstat as-overview (block "Assigned by ARIN")

Allocated

1989-06-30 (ARIN autnum TOP-LEVEL registration event for the DNIC block, first-party RIR date — NOT an IEEE date); last changed 2025-09-12 [Confirmed] — ARIN RDAP autnum/325 top-level events (corroborated by A2, A3, A5)

Org status

active; ARIN status "active"; block last changed 2025-09-12; AS325 listed under PeeringDB DoD org 17705 [Confirmed] — ARIN RDAP autnum/325, peeringdb.com/org/17705

Contacts

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

[Confirmed] — ARIN RDAP autnum/325, RIPEstat abuse-contact-finder

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal as of 2026-06-28 — absent from Spamhaus ASN-DROP, CleanTalk ASN, AbuseIPDB ASN view, community bad-ASN GitHub lists, and NANOG/seclists archives; only routing note is bgp.he.net "announces bogons" (lax bogon/RPKI filtering, not active abuse). DoD space can appear in scanning noise from authorized DoD vuln-scan programs (ACAS)

Network & routing

Network type

government/military stub AS; classified "content" by bgp.tools; single intra-DoD upstream/neighbour (AS306); no transit or commercial ISP role [Confirmed] — bgp.tools/as/325, bgp.he.net/AS325

Size

35 IPv4 prefixes (aggregates 55.43.0.0/16 + 55.191.0.0/16 ≈ 131,072 addresses, plus /24 deaggregates) and 2 IPv6 /40 prefixes observed in the 2026-06-14→2026-06-26 window; 0 active prefixes as of 2026-06-28 [Confirmed] — RIPEstat announced-prefixes / routing-status

Routing/peering

NOT currently announced (announced=false; routing-status 0 v4 / 0 v6 prefixes as of 2026-06-28); 1 observed BGP neighbour; when active, broadly visible (324/326 v4 RIS peers, 323/323 v6); first seen 2011-07-22, last seen 2026-06-26T16:00:00 [Confirmed] — RIPEstat as-overview / routing-status. No public peering policy; no IXP presence found

[Confirmed for absence] — peeringdb.com/org/17705

Upstreams / peers / AS rank / customer cone

Unknown — not returned in the canonical fetch; routing-status names only a count (1 neighbour), not the identity; CAIDA rank/cone not fetched [Unknown] — RIPEstat routing-status (no named neighbour); CAIDA not consulted

RPKI

not determinable for AS325 specifically (rpki-validation skipped, no --prefix supplied); bgp.he.net shows no ROA coverage and notes the network "announces bogons" [Likely] — bgp.he.net/AS325

Notable usage

announces 55.0.0.0/8 DoD space (55.43.0.0/16, 55.191.0.0/16); prefix descriptions consistently labeled "Headquarters, USAISC" (former U.S. Army Information Systems Command), one prefix labeled "United States Department of Defense (DoD)" directly

[Confirmed] — bgp.he.net/AS325, bgp.tools/as/325, ipinfo.io/AS325

Block / assignment

member of DoD block DNIC-ASBLK-00306-00371 (AS306–AS371, 66 ASNs), held under single autnum handle AS306 [Confirmed] — ARIN RDAP autnum/325, cidr-report reserved-ases

Analyst note

Encountered as a DoD legacy stub ASN inside the DNIC-ASBLK-00306-00371 block; the /autnum/325 RDAP query resolves to the parent block record (handle AS306), so registrant, block name, and the 1989-06-30 allocation date are block-level facts that apply to AS325. Currently withdrawn from the global table (0 prefixes) but recently active; clean security record.