AS19

AS19 is a legacy single-digit allocation registered under ARIN to Leidos, Inc., the Reston, VA defense and IT-services corporation — not the "Center for Seismic Studies," which is the historical name and the most likely point of analyst confusion. RFC 1020/1166 list AS19 as "CSS-DOMAIN" (Center for Seismic Studies), an organizational unit operated by Science Applications International Corporation (SAIC) under DARPA seismic- and nuclear-test-monitoring work. The lineage to today's holder is corporate: per SAIC's September 2013 SEC filings, the pre-2013 SAIC renamed itself Leidos Holdings and spun off a new company also called SAIC, with Leidos (NYSE: LDOS) retaining the original corporate history and network assets — which is why this legacy ASN stayed with Leidos. It actively announces 149.8.0.0/16 (plus the more-specific 149.8.128.0/17), about 65,536 IPv4 addresses, with roughly three upstreams and three peers. For triage this is a defense/IT-services corporate network; the famous "Center for Seismic Studies" name is historical only, and the ASN is currently actively routed. The ARIN ASN RegDate of 1984-07-27 is the registry date (the org record's 2013 date reflects the SAIC→Leidos rename, not the original assignment). No notable public abuse signal was found as of June 2026.

Operator

Leidos, Inc. (ARIN OrgId LEIDO, Reston, VA) [Confirmed] — ARIN RDAP

Country / RIR

US, ARIN [Confirmed]

Allocated

ARIN ASN RegDate 1984-07-27 (registry date; org LEIDO RegDate 2013-10-31 reflects SAIC→Leidos rename, NOT original assignment) [Confirmed for shown date]

Org status

active (lineage: Center for Seismic Studies → SAIC → Leidos, 2013) — leidos.com

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-08; corporate network — bgpview.io

Network & routing

Network type

enterprise / government-contractor (defense & IT services) [Confirmed]

Size

announces 149.8.0.0/16 (+ 149.8.128.0/17); ~65,536 IPv4 addrs — bgp.he.net / bgp.tools (2026-06)

Routing/peering

actively announcing; ~3 upstreams, 3 peers; RPKI unknown — ipinfo.io, bgp.he.net

Notable usage

[historical] RFC 1020/1166 "CSS-DOMAIN" = Center for Seismic Studies, an SAIC unit under DARPA seismic/nuclear-test-monitoring work. [current] held by Leidos, Inc. (legal successor of pre-2013 SAIC after the 2013 rename/spin-off) — leidos.com

Related ASNs

SAIC/Leidos corporate space; no specific sibling confirmed for this profile

Analyst note

A defense/IT-services corporate network; the "Center for Seismic Studies" name is historical only. Currently actively routed.