Adder Technology Limited — single MA-L block (00:0F:58)

Adder Technology Limited is a UK-based manufacturer of KVM (keyboard-video-mouse) and AV-over-IP switching hardware, holding a single IEEE MA-L block, 00:0F:58, registered under the company's Cambridgeshire address. Unlike many networking OUI registrants that turn out to be shell entities with no independent footprint, Adder is a long-running, identifiable business: UK Companies House records the entity (company number 01823478) as incorporated in June 1984, and the company maintains an active product catalog today, including the ADDERLink XDIP and XD-series IP-based KVM extenders and the ADDERView Secure line marketed for classified and defense environments with NIAP/EAL4+ certification claims on some models. Two independent MAC-vendor lookup services (hwaddress.com and the macvendors.com API) each resolve addresses beginning 00:0F:58 to Adder Technology Limited, corroborating the IEEE registry data from a separate angle. No second OUI block was found for this vendor, so the entry rests on one MA-L assignment, but the surrounding company and product evidence clears the bar for a genuine, non-shell vendor page rather than a bare-registration stub.

OUI assignment

00:0F:58 (single MA-L block, hex 000F58) [Confirmed] — the IEEE MA-L registry

Registry / block size

MA-L (24-bit OUI) [Confirmed] — the IEEE MA-L registry

Organization name / address

Adder Technology Limited, Technology House, Bar Hill, Cambridgeshire, GB, CB3 8SQ [Confirmed] — the IEEE MA-L registry; cross-confirmed by hwaddress.com and the macvendors.com API independently resolving 00:0F:58 addresses to the same organization

Date registered

Unknown — IEEE's public OUI registry (the IEEE MA-L registry columns: Registry, Assignment, Organization Name, Organization Address) publishes no assignment/registration date for MA-L entries; none is attributed here, and any third-party "date registered" figure would be a database artifact, not an IEEE fact. [Confirmed as Unknown]

Corporate identity

matches UK Companies House entity ADDER TECHNOLOGY LIMITED, company number 01823478, incorporated 11 June 1984 [Likely] — https://find-and-update.company-information.service.gov.uk/company/01823478 (single primary-registry source; corroborated informally by companycheck.co.uk but not by a second official registry)

Company status

active, currently operating with a live product catalog [Confirmed] — https://www.adder.com/en

Device / product types

IP-based KVM and AV-over-IP extenders/switches (ADDERLink XDIP, XD642, XD-C650), ADDERView RDX, and the ADDERView Secure line for classified/defense use (NIAP PP 4.0 / EAL4+ claims on some models)

[Likely] — https://www.adder.com/en/kvm-solutions/adderlink-xdip, https://www.adder.com/en/kvm-solutions/secure

Second-source corroboration

macvendors.com API independently resolves 00:0F:58:00:00:00 to "Adder Technology Limited," agreeing with hwaddress.com's lookup [Confirmed] — https://api.macvendors.com/00:0F:58:00:00:00, https://hwaddress.com/oui-iab/00-0F-58/

Multiple-OUI check

no second OUI block found for Adder Technology under targeted registry and web searches; entry substance rests on company/product identifiability rather than multiple assignments

[Confirmed absence within search scope] — the IEEE MA-M registry, the IEEE MA-S registry (no genuine match); hwaddress.com, macvendors.com searches

Security/CVE note

no CVEs specific to Adder Technology KVM hardware were found; unrelated Linux-kernel "KVM" hypervisor CVEs are a naming collision and not a finding about this vendor's products [Confirmed absence within search scope] — general web/CVE search, no citable positive source

Analyst note

single-OUI registrant, but verifiable company substance (1984 UK incorporation on record, active current product line, named device families, two independent MAC-vendor corroborations) clears the abstain bar set for bare single-OUI shell registrants.