AS128

AS128 is a low-numbered legacy Autonomous System Number registered through ARIN under the name ADS-AS, with the current registrant being Booz Allen Hamilton Inc. (org handle BAH-2-Z, 8283 Greensboro Drive, McLean, VA 22102). The ADS-AS handle preserves the original assignee, Advanced Decision Systems Inc. — a Mountain View, California artificial-intelligence and decision-support firm that did defense research and was reportedly acquired by Booz Allen Hamilton around 1991; that early history is corroborated by only a small number of sources and is treated here as likely rather than confirmed. The ARIN RDAP registration date is 1987-09-23; the autnum object was last changed 2024-04-10. Operationally the ASN is dormant: RIPEstat, CAIDA, and Hurricane Electric all independently show zero announced prefixes in both IPv4 and IPv6, no visible peers, and no presence in the global routing table — RIPEstat reports 0 of 326 RIS peers (v4) and 0 of 320 (v6) seeing it, and CAIDA ranks it 79459 with a customer cone of just itself. The last time it appeared in the routing table was approximately July 2023 per a single tracker. PeeringDB carries an "Open" peering policy, but with nothing announced this is a legacy entry rather than an active stance. No notable public abuse signal was found as of 2026-06-12. Booz Allen's active BGP presence is AS7281, not AS128.

Operator

Booz Allen Hamilton Inc. (ARIN org handle BAH-2-Z; McLean, VA) — current RDAP registrant; ADS-AS handle reflects original assignee [Confirmed] — https://rdap.arin.net/registry/autnum/128

Country / RIR

US, ARIN [Confirmed] — https://whois.arin.net/rest/asn/AS128

Allocated

ARIN RDAP RegDate 1987-09-23 [Confirmed] — ARIN RDAP; autnum last changed 2024-04-10 — https://rdap.arin.net/registry/autnum/128

Org status

active registrant (Booz Allen Hamilton Inc., publicly traded, HQ McLean VA); ASN itself dormant/unrouted [Confirmed] — https://en.wikipedia.org/wiki/Booz_Allen_Hamilton

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-12 (absent from Spamhaus botnet reports, CleanTalk ASN blacklist, AbuseIPDB, NANOG archives); dormant routing state produces no traffic surface

Abuse contact

internet_dns@bah.com (ARIN RDAP / RIPEstat abuse-contact-finder)

Network & routing

Network type

corporate/enterprise (government-contractor) legacy ASN; effectively inactive — 0 announced prefixes [Confirmed] — https://bgp.tools/as/128

Routing status

dormant / not in global routing table as of 2026-06; 0 IPv4 prefixes, 0 IPv6 prefixes, 0 peers, 0 upstreams; RIPEstat RIS peers seeing it 0/326 (v4), 0/320 (v6) [Confirmed] — https://stat.ripe.net/data/routing-status/data.json?resource=128 ; https://bgp.he.net/AS128

Size / rank

CAIDA AS rank 79459; customer cone 1 ASN (itself), 0 prefixes, 0 addresses; not a clique member, not observed [Confirmed] — https://api.caida.org/as-rank/v1/nodes/128

Peering policy

PeeringDB lists "Open" (no ratio/contract requirement), but it is a legacy record — no active peering is observable [Confirmed for listing; activity none] — https://www.peeringdb.com/asn/128

RPKI

no ROAs detected; nothing announced to cover, so no originated routes to protect [Confirmed] — https://bgp.he.net/AS128

Notable usage

low-numbered legacy ASN whose ADS-AS handle preserves Advanced Decision Systems; now held by Booz Allen Hamilton (NYSE: BAH), a major U.S. government/defense technology contractor whose active routed ASN is AS7281 [Confirmed for current holder + AS7281] — https://bgp.tools/as/7281

Related ASNs

AS7281 (Booz Allen Hamilton's active routed ASN) [Confirmed] — https://bgp.tools/as/7281

Original assignee

Advanced Decision Systems Inc. (Mountain View, CA defense AI firm; reportedly acquired by Booz Allen ~1991; some sources associate it with SRI International) [Likely] — https://www.inknowvation.com/sbir/companies/advanced-decision-systems-inc

Last seen routing

approximately 2023-07-30 (single-source historical) [Likely] — https://bgp.he.net/AS128

Analyst note

RDAP registrant (Booz Allen) is authoritative; "Advanced Decision Systems" shown on PeeringDB/ipinfo is the original assignee, not the current holder. A community angle speculated a reserved/RFC-3155 special-use status — this is contradicted by RDAP (a normally-allocated ARIN ASN to a real org) and is not carried.