Siemens AG is the German industrial-technology conglomerate (HQ Munich) whose OUI footprint reflects the breadth of its hardware divisions. Under the bare registrant name "Siemens AG" / "SIEMENS AG", IEEE has assigned roughly 20 MA-L (24-bit) blocks, registered to a cluster of German addresses — most commonly Werner-von-Siemens-Str. 50, Amberg (92224) and Oestliche Rheinbrückenstrasse 50, Karlsruhe (76181/76187) — plus Regensburg, Erlangen, Munich, and Fürth sites. A handful of finer-grained allocations also carry Siemens AG variant names: MA-M /28 sub-allocations 3C:24:F0:90/28 (Siemens Deutschland Mobility, Munich) and F0:40:AF:A0/28 (Karlsruhe) — each carved from a shared IEEE MA-M parent base whose other /28 slices belong to unrelated organisations — and the MA-S prefix 70:B3:D5:C8:7 (Erlangen). The network-visible hardware behind these blocks is dominated by industrial automation and communication gear — SCALANCE industrial Ethernet switches/routers/WLAN, SIMATIC NET and SIMATIC S7 controllers, ET 200 distributed I/O, and PROFINET field devices — so an Siemens OUI on a network strongly implies an OT/ICS or factory-automation context rather than ordinary IT. One important slug caveat: the site's normaliseName() strips the legal-entity token "ag", so every bare "Siemens AG" entry normalises to the slug siemens, not siemens-ag — the publishable vendor page for this group is /mac/vendor-siemens, and no siemens-ag slug is generated. For asset-inventory and security work, the security surface is significant: SCALANCE and PROFINET products carry numerous CISA ICS advisories and CVEs (DoS, buffer-overflow, local privilege-escalation classes), making OUI-based identification of Siemens gear a common first step in ICS asset discovery.
- IEEE assignment (bare name)
- ~20 MA-L prefixes → "Siemens AG" / "SIEMENS AG", registered across German sites (Amberg, Karlsruhe, Regensburg, Erlangen, Munich, Fürth) [Confirmed] — IEEE MA-L (enrichment/registries/oui.csv)
- Registry / block sizes
- primarily MA-L (24-bit OUI); also MA-M /28 sub-allocations 3C:24:F0:90/28 and F0:40:AF:A0/28 (Siemens AG variant names, each carved from a shared MA-M parent base) and MA-S 70:B3:D5:C8:7 [Confirmed] — IEEE MA-L/MA-M/MA-S (enrichment/registries/oui.csv, mam.csv, oui36.csv)
- Sample MA-L prefixes (Siemens AG)
- 08:00:06, 00:01:E3, 00:0B:A3, 00:0E:8C, 00:1B:1B, EC:1C:5D, AC:64:17, 28:63:36, 88:3F:99, D4:F5:27 [Confirmed] — IEEE MA-L / maclookup.app
- MA-M variants
- 3C:24:F0:90/28 ("Siemens AG - Siemens Deutschland Mobility", Otto-Hahn-Ring 6, Munich, DE 81379) — a /28 sub-allocation of the SHARED 3C:24:F0 MA-M base (sibling /28s 3C24F00–3C24F0E belong to 15 unrelated orgs, e.g. Swissdotnet, Sivat, COMATIS, Laipac); F0:40:AF:A0/28 ("SIEMENS AG", Oestl. Rheinbrueckenstr. 50, Karlsruhe, DE 76187) — a /28 sub-allocation of the SHARED F0:40:AF MA-M base (sibling /28s F040AF0–F040AFE belong to 15 unrelated orgs, e.g. ROBOX, Flextronics, Raspberry Pi Trading, Nuro.ai) [Confirmed] — IEEE MA-M (enrichment/registries/mam.csv)
- MA-S variant
- 70:B3:D5:C8:7 ("Siemens AG", MO TPE RE PI, Erlangen, Bavaria, DE 91052) [Confirmed] — IEEE MA-S (enrichment/registries/oui36.csv)
- HQ / country
- Germany (corporate HQ Munich); dominant registry address Werner-von-Siemens-Str. 50, Amberg, Bavaria, DE 92224 [Confirmed] — IEEE MA-L / udger.com
- Company status
- active [Confirmed] — siemens.com
- Device types
- SCALANCE industrial Ethernet switches/routers/WLAN and security appliances; SIMATIC NET / SIMATIC S7 controllers; ET 200 distributed I/O; PROFINET IO field devices, couplers, CP modules; building, healthcare, mobility/transportation, and energy-automation hardware [Likely] — siemens.com, netify.ai, runzero.com (third-party device taxonomy, not an IEEE field)
- Slug resolution
normaliseName() strips the "ag" legal-entity token, so bare "Siemens AG" entries normalise to the site slug siemens (~20 MA-L prefixes grouped), NOT siemens-ag; no siemens-ag slug is generated. Publishable target is /mac/vendor-siemens. [Confirmed] — scripts/generate-oui-pages.js (normaliseName + slugify). NOTE: the requested entry label vendor-siemens-ag does not map to a generated page; W1-web asserted the vendor-siemens-ag slug but cited no source for it.- Grouping caveat
- the site's
siemens bucket also pulls in B8:7A:C9 (Siemens Ltd., Bayswater, Victoria, AU 3153) and 00:1B:1B ("Siemens AG," with trailing comma) into the same normalised group as the German Siemens AG entries [Confirmed] — scripts/generate-oui-pages.js, enrichment/registries/oui.csv
- Related vendors
- vendor-siemens-industrial-automation (Chengdu, 4 prefixes) and vendor-siemens-rail-automation (Siemens Rail Automation SAU, 90:DA:F9) are separately enriched subsidiaries [Confirmed] — enrichment/oui/
- No IEEE date
- IEEE's public OUI data (oui.csv columns: Registry, Assignment, Organization Name, Organization Address) publishes NO assignment/registration date. Third-party tools (maclookup.app) cite 22 Apr 1998 with 08:00:06 as the oldest block — these are database artifacts, NOT IEEE facts. The 08:00:06 block sits in the early 08:00:xx Ethernet range and predates any such artifact date. [Confirmed] — IEEE oui.csv, maclookup.app
- Security context
- Siemens OT/ICS hardware carries a significant CVE surface — PROFINET DoS (CVE-2020-28400, CVE-2019-10936), SCALANCE web-server heap/buffer overflows, SCALANCE LPE9403 stack overflow (local privilege escalation), and multiple CISA ICS advisories (e.g. ICSA-25-259-03). Siemens mitigations: keep devices behind firewalls, restrict exposure, apply firmware patches. [Confirmed] — cisa.gov ICS advisories, runzero.com, securityweek.com
- Analyst note
- A Siemens OUI on a globally-administered address identifies genuine Siemens hardware and most likely an OT/ICS or industrial-automation asset; useful as a first pass for ICS asset inventory, but confirm product line via deeper fingerprinting. IANA Reference: blank (OUI/MAC entries have no IANA reference).