DELL N3000 User Manual

Configuring Connectivity Fault Management

This chapter describes how to configure the Connectivity Fault Management 

feature, which is specified in IEEE 802.1ag (

IEEE Standard for Local and 

Metropolitan Area Networks Virtual Bridged Local Area Networks 

Amendment 5: Connectivity Fault Management). This protocol, also known 

as Dot1ag, enables the detection and isolation of connectivity faults at the 

service level for traffic that is bridged over a metropolitan Ethernet LAN. 
This feature is supported only on the Dell Networking 4000 series switches.
The topics covered in this chapter include:

• Dot1ag Overview
• Default Dot1ag Values
• Configuring Dot1ag (Web)
• Configuring Dot1ag (CLI)
• Dot1ag Configuration Example

With the emergence of Ethernet as a Metropolitan and Wide-Area 

Networking technology, different operators often work together to provide 

end-to-end services to enterprise customers. This has driven the need of a 

new set of OAM (Operations, Administration, and Maintenance) Protocols.
Service-Level Connectivity Fault Management (CFM) is the OAM protocol 

provision for end-to-end service-layer instances in carrier networks. CFM 

provides mechanisms to support the administrator in performing connectivity 

checks, fault detection, fault verification and isolation, and fault notification 

per service in the network domain of interest. Unlike Ethernet OAM (IEEE 

802.3ah), where the faults are detected and notified on a single point-to-point