Cisco is among the largest OUI holders on the registry, with roughly 1,232 MA-L blocks registered to "Cisco Systems, Inc" (the registry renders it without a trailing period). The oldest and most famous block, 00:00:0C, dates to the early Internet and still shows the address 170 West Tasman Drive, San Jose, while most newer Cisco blocks show 80 West Tasman Drive — both Cisco's San Jose campus. A Cisco OUI in switch or ARP tables almost always indicates infrastructure — routers, switches, IP phones, wireless access points, firewalls — rather than an endpoint, and the gear commonly displays MACs in Cisco's dotted-triplet notation (e.g. 0000.0c12.3456) rather than colon-separated form. The important consolidation detail is that several Cisco subsidiaries keep their own distinct OUIs rather than folding into the Cisco Systems registrant: Cisco Meraki (~57 prefixes) for cloud-managed wireless and switching, acquired in a deal announced 18 November 2012 and completed 20 December 2012 for about $1.2 billion; Cisco-Linksys, LLC (~25 prefixes) from the consumer-networking era; and Cisco SPVTG (~41 prefixes), the Scientific-Atlanta set-top-box lineage. For triage, a Meraki-prefixed device specifically signals cloud-managed Meraki hardware, which is operationally distinct from traditional Catalyst/Nexus/IOS gear. IEEE rules let acquired brands retain their original registrant names, which is exactly why these subsidiary OUIs don't read as "Cisco."
- IEEE assignment
- ~1,232 prefixes → Cisco Systems, Inc, registered San Jose, CA, US [Confirmed] — IEEE MA-L
- Registry / block size
- MA-L (24-bit OUI); holds ~1,232 IEEE prefixes (~20.7B addresses) [Confirmed] — maclookup.app (IEEE-sourced, prefix count is a current third-party snapshot and drifts). NOTE: IEEE's public OUI data publishes NO assignment/registration date (oui.csv columns are only Registry, Assignment, Organization Name, Organization Address); any "date registered" on third-party tools is a database artifact, not an IEEE fact. Cisco's 00:00:0C was in shipping hardware in the late 1980s, so no late-1990s artifact date can be its assignment date.
- HQ / country
- 170 West Tasman Drive, San Jose, CA 95134-1706, US on the oldest (00:00:0C) block; 80 West Tasman Drive, San Jose on most newer blocks — both Cisco's San Jose campus [Confirmed] — IEEE MA-L
- Company status
- active [Confirmed] — cisco.com
- Device types
- routers, switches, IP phones, wireless access points, firewalls, set-top boxes [Confirmed] — cisco.com
- Notable products
- Catalyst, Nexus, ISR/ASR routers, ASA firewalls, IOS/IOS-XE devices, Aironet APs
- Verified sample prefixes (Cisco Systems, Inc, MA-L)
- 00:00:0C (170 West Tasman Drive), 00:1B:0C, 00:0C:CE (80 West Tasman Drive) [Confirmed] — IEEE MA-L / maclookup.app
- Historic context (pre-1998 hardware)
- 00:00:0C is a very low-numbered early block; Cisco shipped the Ethernet-capable AGS router in 1986 (AGS+ in 1989), so 00:00:0C-prefixed hardware existed in the late 1980s — well before any third-party "1998" artifact date. [Confirmed AGS 1986 ship date; exact IEEE assignment year not published] — cisco.com / Cisco company history
- Special note
- Subsidiaries hold their own OUIs under their own registrant names — Cisco Meraki (~57 prefixes; acquired, announced 2012-11-18, completed 2012-12-20, ~$1.2B), Cisco-Linksys, LLC (~25), Cisco SPVTG (~41, Scientific-Atlanta lineage). Cisco devices often show dotted-triplet MAC notation (0000.0c12.3456). [Confirmed] — newsroom.cisco.com, techcrunch.com, maclookup.app
- Related vendors
- parent of Cisco Meraki, Cisco-Linksys, Cisco SPVTG (Scientific Atlanta)
- Analyst note
- A Cisco OUI almost always indicates infrastructure (routers, switches, phones, APs), not an endpoint; Meraki-prefixed devices indicate cloud-managed Meraki gear.