D&M Holdings Inc. — 3 prefixes (MA-L)

A MAC address beginning with 00:05:CD, 00:06:78, or 8C:A9:6F belongs to D&M Holdings Inc., typically seen on network-connected home-theater and audio-visual receivers rather than computers or mobile devices. D&M Holdings was the parent company behind the Denon and Marantz audio brands before being folded into Sound United in 2017.

D&M Holdings Inc. holds all three of these MA-L prefixes according to the site's cached canonical IEEE registry (the IEEE MA-L registry), each registered to "D&M Holdings Inc." at D&M Building, 2-1 Nisshin-cho, Kawasaki-shi, Kanagawa, JP 210-8569. maclookup.app, a third-party aggregator of IEEE OUI data, independently corroborates the same three prefixes. One of them, 00:05:CD, has been observed in the wild on Denon AV receivers such as the AVR-3808CI, which corroborates the vendor identification with a real device sighting rather than a bare registration alone.

All three prefixes were directly located in the site's cached IEEE the IEEE MA-L registry snapshot under the registrant string "D&M Holdings Inc." — the initial lookup normalised the slug ("dm-holdings") rather than searching the registrant name, which is why an earlier pass reported no local match. The company and prefix match is Confirmed against the canonical registry, not merely Likely.

maclookup.app lists 2001-06-04 and 2019-02-15 as "registration"/"update" dates for these prefixes — these are aggregator database artifacts, not IEEE-published facts, since IEEE's public OUI data carries no assignment-date field. No security vulnerability or abuse signal was found tied to this OUI; only an unrelated 2020 Denon/Marantz HEOS firmware connectivity bug (a functional issue, not a security one) turned up in search.

IEEE assignment

3 prefixes → D&M Holdings Inc. [Confirmed] — the IEEE MA-L registry; maclookup.app (corroborating)

Registry / block size

MA-L (24-bit OUI); 3 known prefixes [Confirmed] — the IEEE MA-L registry; maclookup.app

HQ / country

D&M Building, 2-1 Nisshin-cho, Kawasaki-shi, Kanagawa, JP 210-8569; country JP [Confirmed] — the IEEE MA-L registry

Company status

dissolved/absorbed into Sound United (2017); Denon and Marantz brands continue under that parent [Likely] — forbes.com, en.wikipedia.org (D+M Group)

Device types

AV receivers, home-theater / network-audio equipment [Likely] — maclookup.app, bugs.launchpad.net

Notable products

Denon AVR-3808CI (and related Denon/Marantz AV receiver lines) [Likely] — bugs.launchpad.net

Verified sample prefixes

00:05:CD, 00:06:78, 8C:A9:6F [Confirmed] — the IEEE MA-L registry; maclookup.app

Historic block

Unknown — no earlier/historic block identified [Unknown]

Local IEEE registry cache

all three prefixes found in the IEEE MA-L registry under registrant "D&M Holdings Inc." (00:05:CD, 00:06:78, 8C:A9:6F); the initial lookup had normalised the slug ("dm-holdings") instead of searching the registrant name, which produced an earlier false absence [Confirmed] — the IEEE MA-L registry

Special note

maclookup.app lists 2001-06-04 (00:05:CD, 00:06:78) and 2019-02-15 (8C:A9:6F) as "registration"/"update" dates — these are aggregator database artifacts, not IEEE-published facts; IEEE's public OUI data carries no assignment-date field [Confirmed] — maclookup.app

Related vendors

Denon, Marantz (brands under the former D&M Holdings / D+M Group, now Sound United) [Likely] — en.wikipedia.org (D+M Group); Sound United itself is a separate IEEE registrant in the cached registry, holding MA-L 94:4F:4C (Sound United LLC, One Viper Way, Vista, CA, US) and MA-M B0:1F:81:3 (Sound United, Owings Mills, MD, US), not consolidated into this entry

[Confirmed] — the IEEE MA-L registry; the IEEE MA-M registry

Security/abuse signal

none found; only an unrelated 2020 HEOS firmware connectivity bug (functional, not security) surfaced in search [Unknown] — avforums.com

Analyst note

this OUI identifies legacy Denon/Marantz-era network-audio hardware; the parent company no longer operates independently, having been absorbed into Sound United, so treat this as a historical/legacy vendor rather than an active registrant [Likely] — en.wikipedia.org, forbes.com