AS53

AS53 is a legacy allocation registered under ARIN to Northrop Grumman Corporation – Automation Sciences Laboratory (OrgId NGCASL, Pico Rivera, CA), an early corporate research allocation tied to the legacy 140.188.0.0/16 block. AS53 itself is dormant in 2026 — it is not observed announcing any prefix. The key triage point is a reallocation: the historic 140.188.0.0/16 space is being broken up, and 140.188.64.0/18 was reallocated on 2025-06-11 to PEG TECH INC (ARIN OrgId PT-82, Santa Clara, CA), now originated by AS54600 (PEG-SV) with upstream AS3491 (PCCW Global) — so that block has left Northrop's control, even though residual reverse-DNS still references northropgrumman.com. The ARIN ASN RegDate is 1985-12-24 (autnum updated 1996-06-10; org entity RegDate 1985-01-29). Northrop Grumman's main active ASN is AS1906 (announcing on the order of dozens of IPv4 prefixes, including legacy TRW/Litton/Grumman Data Systems space, peering with AT&T AS7018), and AS207173/AS207900 are Northrop Grumman UK (RIPE/GB). For triage, treat AS53 as a dormant legacy holder — and flag that IP-to-org enrichment keyed to the historic AS53/Northrop association will be wrong for 140.188.64.0/18 after June 2025, where it should resolve to PEG TECH INC / AS54600. No notable public abuse signal was found as of June 2026.

Operator

Northrop Grumman Corporation – Automation Sciences Laboratory (ARIN OrgId NGCASL, Pico Rivera, CA 90660) [Confirmed] — ARIN RDAP

Country / RIR

US, ARIN [Confirmed]

Allocated

ARIN ASN RegDate 1985-12-24 (autnum updated 1996-06-10; org RegDate 1985-01-29) [Confirmed]

Org status

legacy/dormant — successor operational ASN is AS1906

Security/abuse context (NEUTRAL, DATED)

no public abuse signal attributable to AS53; dormant — whois.ipip.net

Network & routing

Network type

enterprise / defense contractor (legacy) [Confirmed]

Size

dormant — AS53 not observed announcing any prefix — bgp.tools (2026-06)

Routing/peering

none from AS53; RPKI n/a — bgp.tools

Notable usage

[historical] early corporate research allocation tied to Northrop's Automation Sciences Laboratory and legacy 140.188.0.0/16 — northropgrumman.com

Related ASNs

AS1906 (Northrop Grumman main, active); AS207173/AS207900 (Northrop Grumman UK, RIPE/GB); AS54600 (PEG TECH INC — now holds 140.188.64.0/18) [Confirmed]

REALLOCATION FLAG

historic 140.188.0.0/16 broken up; 140.188.64.0/18 reallocated 2025-06-11 to PEG TECH INC (ARIN OrgId PT-82, Santa Clara, CA), now originated by AS54600 (PEG-SV), upstream AS3491 (PCCW Global); residual rDNS still references northropgrumman.com [Confirmed] — ARIN RDAP

Analyst note

Treat AS53 as a dormant legacy holder. Key triage point: 140.188.64.0/18 is now PEG TECH INC (AS54600), not Northrop — IP-to-org logic keyed to AS53/Northrop will be wrong for that block after June 2025.