Castlenet Technology Inc. — 5 prefixes (MA-L)

Castlenet Technology Inc. is a Taiwanese network-equipment manufacturer that holds five IEEE MA-L (24-bit OUI) blocks: FC-4A-E9, 98-F2-17, 18-48-59, 00-30-54, and 00-1C-7B. Founded in 1998 and listed on the Taipei Exchange (TPEX:8059), Castlenet operates as a subsidiary of Kinpo Electronics and builds broadband customer-premises equipment on an OEM/ODM basis — cable modems (DOCSIS/EMTA), ADSL CPE, voice gateways, and mesh Wi-Fi systems — for cable and telco operators. The five prefixes carry two distinct registered addresses: four blocks list 5F., No. 10, Daye Rd., Beitou District, Taipei City, while 18-48-59 lists Beishen Rd., Shenkeng District, New Taipei City, most plausibly reflecting a relocation or a secondary registered address (IEEE does not date-stamp which came first). Because the OUIs appear on ISP-provisioned edge hardware, they are useful for identifying operator-deployed modems and gateways in the field. One security note is well documented: several CastleNet cable-modem models (CBV734EW, CBV38Z4EC/ECNIT, CBW383G4J, CBW38G4J, CBW700N) were named among devices affected by CVE-2017-5135 ("StringBleed"), an SNMPv1/v2 community-string authentication bypass allowing unauthenticated remote read/write MIB access. Consolidating all five blocks into a single vendor entry is more useful than five near-identical per-prefix pages.

IEEE assignment

5 MA-L prefixes → Castlenet Technology Inc., Taipei / New Taipei City, TW [Confirmed] — IEEE MA-L, corroborated by maclookup.app

Registry / block size

MA-L (24-bit OUI); 5 IEEE prefixes; no MA-M or MA-S registrations found for this org name [Confirmed] — the IEEE MA-L registry, the IEEE MA-M registry, the IEEE MA-S registry. NOTE: IEEE 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 (e.g. maclookup.app's "25 February 2014") is a database artifact, not an IEEE fact — not recorded here.

HQ / country

5F., No. 10, Daye Rd., Beitou Dist., Taipei City 112030, TW (registry address on 4 of 5 blocks); 18-48-59 lists 5th Fl., No.159-1, Sec.3, Beishen Rd., Shenkeng Dist., New Taipei City 222004, TW [Confirmed] — IEEE MA-L

Company status

active; publicly traded (Taipei Exchange TPEX:8059); subsidiary of Kinpo Electronics; established 1998 [Likely] — https://www.crunchbase.com/organization/castlenet-technology, https://stockanalysis.com/quote/tpex/8059/company/ (corporate self-description on castlenet.com.tw returned HTTP 403 on direct fetch; profile relied on search-indexed content + financial-profile sites)

Device types

cable modems (DOCSIS / EMTA), ADSL CPE, voice gateways, mesh Wi-Fi systems [Likely] — corporate profile + FCC filing https://fccid.io/RK9-CBV383Z2/User-Manual/Users-Manual-2521804 (grantee RK9, model CBV383Z2 cable modem)

Notable products

CBV383Z2, and CastleNet-branded cable modems CBV734EW / CBV38Z4EC / CBW383G4J / CBW38G4J / CBW700N

Verified prefixes (all MA-L, Castlenet Technology Inc.)

FC-4A-E9, 98-F2-17, 18-48-59, 00-30-54, 00-1C-7B [Confirmed] — the IEEE MA-L registry

Security context

several CastleNet cable-modem models named among devices affected by CVE-2017-5135 ("StringBleed"), an SNMPv1/v2 community-string auth bypass enabling unauthenticated remote read/write MIB access; disclosed 2017. No further Castlenet-specific CVEs found (absence is not a guarantee). [Likely] — https://nvd.nist.gov/vuln/detail/CVE-2017-5135, https://www.bleepingcomputer.com/news/security/several-cable-modem-models-affected-by-snmp-god-mode-flaw/

Related vendors

parent company Kinpo Electronics, Inc.

Analyst note

A Castlenet OUI on a globally-administered address identifies genuine Castlenet-manufactured hardware — typically ISP-provisioned cable/DSL CPE. Whether Castlenet holds OUI blocks beyond these five was not exhaustively resolved beyond the IEEE CSV; treat the count as "at least five."