Definition
LAN access mediation encompasses the application of strict access control policies, systematic verification of devices, and authentication mechanisms to govern connectivity to a Local Area Network.
How it works
LAN Access Mediation is a network security approach that manages and controls access to a Local Area Network by using key components such as Access Control Lists (ACLs) to specify which devices are allowed or denied access, Port Security to restrict device connections to specific switch ports, RADIUS for determining the level of access or specific resources available to users or devices, and 802.1X for enforcing device authentication before granting network access. This comprehensive strategy ensures that only authorized devices and users can connect to the network, enhancing overall security.
Implementation perspective
LAN Access Mediation should be treated as a technical defensive capability rather than a product checkbox. In practice, teams should define the protected scope, the conditions under which the technique acts, and the observable evidence that demonstrates the intended behavior. For this technique, likely engineering context includes the relevant system, activity, and evidence sources.
Use the technique to create a logical or physical boundary that limits access, execution, communication, or movement.
Questions to ask
- What is being isolated, from whom or what, and under which conditions?
- Which flows or operations remain explicitly allowed across the boundary?
- What happens when the isolation mechanism fails or loses policy context?
- How is the boundary tested for alternate paths, bypasses, and unintended dependencies?
Evidence and validation
- Architecture and data-flow diagrams showing the isolation boundary
- Policy, rule, or configuration exports from enforcing components
- Tests of allowed, denied, and failure-state behavior
- Monitoring evidence for boundary violations and policy changes
Common failure patterns
- The intended boundary has undocumented alternate paths or inherited trust relationships.
- Rules accumulate without ownership, review, or removal of obsolete exceptions.
- Isolation is assumed from network location while application, identity, or management paths remain open.
This implementation perspective is original Bare Metal Cyber educational content. It does not replace the official D3FEND definition or establish that a specific product implements the technique.
Technique hierarchy
Top-level family
Parent techniques
Direct child techniques
None listed at this level.
Artifacts and ontology entities
These relationships describe how D3FEND connects a defensive technique to artifacts or other ontology entities. They describe graph semantics, not a product certification.
Explicit technique relationships
Authoritative sources
- Open this technique on the official D3FEND website ↗
- Open the official ontology resources ↗
- What is Network Access Control? ↗Fortinet · InternetArticleReference
- Related source ↗
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