AS243

AS243 is a legacy autonomous system number registered under ARIN to L3Harris Technologies, Inc., the major US defense and aerospace contractor headquartered at 1025 W. NASA Blvd, Melbourne, Florida. The ASN name HARRIS-ATD-AS preserves pre-merger Harris Corporation "Advanced Technology Division" branding; Harris Corporation (founded 1895) merged with L3 Technologies on June 29, 2019 to form L3Harris (NYSE: LHX, S&P 500, ~$21.3B revenue and ~47,000 employees as of 2024), and the ARIN registrant was updated to the new legal entity while the historic autnum name was retained. The ARIN top-level autnum registration event dates the allocation to 1988-10-04, with the most recent change recorded 2023-01-31 — both first-party RIR facts. Operationally AS243 is a single-homed stub / enterprise network: it announces IPv4 only (no IPv6 prefixes), originating roughly 131–133 prefixes covering on the order of 750,000 IPv4 addresses across legacy 128.x, 137.x, 142.x and 192.x ranges, including space historically tied to acquired entities. IPinfo classifies it as a "Business" network and bgp.tools tags it as government-related infrastructure, consistent with its defense-contractor operator. RPKI coverage is minimal — only two prefixes (192.52.224.0/23 and 205.142.172.0/22) carry valid ROAs while the remainder rely on unauthenticated IRR records spread across RADB, APNIC, RIPE, LEVEL3 and JPIRR. The abuse and reputation picture is clean as of June 2026: CleanTalk reports a 0.00% spam rate, AS243 is absent from the Spamhaus ASN-DROP feed, and Qrator Radar records zero DDoS amplifiers. Documented L3Harris corporate-security incidents (a 2025 ransomware claim by "World Leaks," a 2023 "Abyss" claim, and an insider trade-secret theft case) sit at the organization level and are not tied to AS243 acting as a network abuse source.

Operator

L3Harris Technologies, Inc. (defense/aerospace contractor; ARIN handle L3HT-Z; HQ 1025 W. NASA Blvd, Melbourne, FL) [Confirmed] — ARIN RDAP autnum/243, ipinfo.io/AS243

AS name

HARRIS-ATD-AS (legacy Harris Corporation "Advanced Technology Division" branding) [Confirmed] — ARIN RDAP autnum/243

Country / RIR

United States, ARIN [Confirmed] — ARIN RDAP autnum/243

Allocated

1988-10-04 (ARIN registry date from the autnum top-level registration event, NOT an IEEE date — IEEE publishes no ASN registration dates); last changed 2023-01-31 [Confirmed] — ARIN RDAP autnum top-level events (A3 fetched via fetch-canonical after A1's entities[] block truncated the top-level events)

Org status

public corporation (NYSE: LHX, S&P 500); formed 2019-06-29 from the Harris Corporation (1895) + L3 Technologies merger; ~$21.3B revenue, ~47,000 employees (2024) [Confirmed] — en.wikipedia.org/wiki/L3Harris, l3harris.com/who-we-are

Contacts

abuse@l3harris.com / +1-321-727-9100 (ABUSE8265-ARIN; L3Harris corporate line); IPAdmins@L3Harris.com (IPADM889-ARIN, NOC/admin/technical); routing/technical POC Michael Whisenant (WHISE34-ARIN, validated) — the POC's personal mailbox is withheld here, consult the ARIN RDAP record directly; dnsadmin@harris.com (ZH41-ARIN, legacy DNS)

[Confirmed] — ARIN RDAP autnum/243

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal as of 2026-06-20 — CleanTalk 0.00% spam rate, absent from Spamhaus ASN-DROP, 0 DDoS amplifiers per Qrator; Qrator also records 13 BGP-hijack incidents (victim/perpetrator role not determinable without authentication) and 71 "vulnerable ports"; a historical bogon-announcement flag at bgp.he.net appears resolved

Network & routing

Network type

single-homed stub / enterprise corporate network; provides no transit; IPv4 only; classified "Business" by IPinfo and tagged government-related by bgp.tools [Confirmed] — ipinfo.io/AS243, bgp.he.net/AS243, bgp.tools/as/243

Size

~131–133 IPv4 prefixes (133 per bgp.he.net, 131 per bgp.tools; one source reported 78); ~750,000 IPv4 addresses (~2,944 /24-equivalents); 0 IPv6 prefixes [Likely for counts; Confirmed for IPv4-only] — bgp.he.net/AS243, bgp.tools/as/243

Routing/peering

observed upstream/peer AS32787 (Akamai/Prolexic) per two sources [Likely]; one source (BGPView via A5) instead reports AS3356 (Lumen) + AS10143 (Exetel) — sources disagree, so the upstream set is not firmly established. No PeeringDB record (peeringdb.com/asn/243 returns 404), hence no public peering policy [Confirmed for no-PeeringDB; Likely for AS32787]

RPKI

partial — only 192.52.224.0/23 and 205.142.172.0/22 carry valid ROAs; no RPKI-invalid origins reported; remaining prefixes are unauthenticated IRR-only [Likely] — bgp.he.net/AS243

Notable usage

internal enterprise/corporate network for L3Harris; legacy IPv4 space across 128.x/137.x/142.x/192.x including ranges historically tied to acquired entities (e.g. Leitch Technology, Jefferson-Pilot Data Services); IRR records present in RADB, APNIC, RIPE, LEVEL3, JPIRR

[Likely] — bgp.he.net/AS243, bgp.tools/as/243

Corporate incidents (org-level, NOT AS243 abuse)

2025 "World Leaks" ransomware data-theft claim; 2023 "Abyss" ransomware claim (L3Harris called it isolated/contained); a former Trenchant GM pleaded guilty in 2025 to stealing cyber-exploit components — none documented as affecting AS243 network infrastructure [Confirmed for incidents; Confirmed they are not tied to AS243] — bleepingcomputer.com, techcrunch.com, cyberdaily.au

Analyst note

legacy enterprise ASN under a major US defense contractor; clean abuse posture but minimal RPKI and unauthenticated-IRR-heavy routing. The upstream/peer set is the one materially conflicting datapoint across angles and is left tagged Likely.