3Com — 43 prefixes (MA-L)

3Com holds 43 MA-L (24-bit OUI) blocks in the IEEE registry, spread across three legal-entity name forms — "3COM" (the US parent at 5400 Bayfront Plaza, Santa Clara, CA), "3COM EUROPE LTD" (older UK addresses on Boundary Way and 3COM Centre, Hemel Hempstead), and "3Com Ltd" (the newer Peoplebuilding 2, Hemel Hempstead address) — plus a handful of legacy addresses tied to single early prefixes (Betsy Ross Drive in Santa Clara, Leghorn Street in Mountain View, and Spring Hill Road in Sharon, NH). All are the same 3Com Corporation, founded in 1979 by Ethernet co-inventor Robert Metcalfe and Howard Charney; the name comes from "Computer Communication Compatibility." 3Com dominated the server NIC market in the late 1990s before Intel undercut it on price, and shipped Ethernet switches, WAN routers, wireless access points, NBX VoIP phones, USRobotics modems, and TippingPoint intrusion-prevention systems. Hewlett-Packard completed its $2.7 billion acquisition of 3Com on April 12, 2010, after which the networking portfolio was folded into HP and later HPE's Aruba unit — so 3Com no longer exists as a standalone vendor and there is no active vendor site. A data-quality trap to avoid: the MA-M block 4C:74:A7:C is assigned to "N3com" in Moscow, RU — an unrelated entity that should not be merged into this record. All 3Com hardware is end-of-life with no vendor security patches, and the line carries an extensive CVE history (vendor 135 on CVEdetails) spanning switch/router DoS, SNMP community-string exposure, OfficeConnect XSS, and FTP-daemon buffer overflows.

IEEE assignment

43 MA-L prefixes → 3COM / 3COM EUROPE LTD / 3Com Ltd (same vendor, three registry name forms) [Confirmed] — IEEE MA-L

Registry / block size

MA-L (24-bit OUI); 43 prefixes [Confirmed] — IEEE MA-L. NOTE: IEEE's public OUI data publishes NO assignment/registration date (the IEEE MA-L registry columns are only Registry, Assignment, Organization Name, Organization Address); any "date registered" on third-party tools is a database artifact, not an IEEE fact.

HQ / country

5400 Bayfront Plaza, Santa Clara, CA 95052, US (registry address); EU subsidiary at Peoplebuilding 2, Hemel Hempstead, Herts HP2 4NW, GB [Confirmed] — IEEE MA-L

Legacy registry addresses

3COM Centre / Boundary Way, Hemel Hempstead HP2 7YU, GB (older EU entries); 5353 Betsy Ross Drive, Santa Clara, CA (prefix 00:26:54); 2133 Leghorn Street, Mountain View, CA (00:D0:D8); 405 Spring Hill Road, Sharon, NH 03458, US (00:02:9C) [Confirmed] — IEEE MA-L

Company status

defunct as a standalone vendor; acquired by Hewlett-Packard, acquisition completed April 12, 2010 ($2.7B); later folded into HPE Aruba [Confirmed] — investor.hp.com (2010 acquisition press release), en.wikipedia.org/wiki/3Com

Founded

1979 by Robert Metcalfe (Ethernet co-inventor) and Howard Charney; name from "Computer Communication Compatibility" [Confirmed] — en.wikipedia.org/wiki/3Com

Device types

network interface controllers (NICs), Ethernet switches, WAN routers, wireless access points, NBX VoIP/IP telephony, USRobotics modems, TippingPoint intrusion-prevention systems [Confirmed] — en.wikipedia.org/wiki/3Com, networkworld.com

Notable acquisitions by 3Com

USRobotics (1997, brought Palm Computing), Chipcom (1995), NBX (1999), TippingPoint (2005), H3C JV with Huawei (remaining stake 2007) [Confirmed] — en.wikipedia.org/wiki/3Com, fastcompany.com

Verified sample prefixes (all MA-L)

00:10:4B, 00:10:5A, 00:20:AF, 00:60:08, 00:60:8C, 00:60:97, 00:A0:24 [Confirmed] — IEEE MA-L / maclookup.app

MA-M / OUI-36

no MA-M or OUI-36 assignments for 3Com the networking vendor. The MA-M block 4C:74:A7:C is "N3com" (Moscow, RU), a different, unrelated entity [Confirmed] — IEEE MA-M

Security note

extensive CVE history (vendor 135 on CVEdetails) — switch/router DoS, SNMP community-string exposure (remote info disclosure / takeover), OfficeConnect XSS, 3CServer/3CDaemon FTP buffer-overflow RCE; all products end-of-life with no vendor patches. Legacy H3C-branded gear from the 2007 Huawei JV drew U.S. government supply-chain scrutiny

[Confirmed] — cvedetails.com/vendor/135, hkcert.org, en.wikipedia.org/wiki/3Com

Analyst note

a 3Com OUI on a globally-administered address reliably identifies legacy 3Com/HP-era hardware; given the company's 2010 absorption and EOL status, such devices in production should be flagged for replacement/security review.