Dell Force10 S4820T S4820T Configuration Guide - Page 80

www.dell.com | support.dell.com There is a need for Layer 2 equivalents to manage and troubleshoot native Layer 2 Ethernet networks. With these tools, you can identify, isolate, and repair faults quickly and easily, which reduces operational cost of running the network. OAM also increases availability and reduces mean time to recovery, which allows for tighter service level agreements, resulting in increased revenue for the service provider. In addition to providing end-to-end OAM in native Layer 2 Ethernet Service Provider/Metro networks, you can also use CFM to manage and troubleshoot any Layer 2 network including enterprise, datacenter, and cluster networks. Maintenance Domains Connectivity Fault Management (CFM) divides a network into hierarchical maintenance domains, as shown in the illustration below. A CFM maintenance domain is a management space on a network that is owned and operated by a single management entity. The network administrator assigns a unique maintenance level (0 to 7) to each domain to define the hierarchical relationship between domains. Domains can touch or nest but cannot overlap or intersect as that would require management by multiple entities. Customer Network Service Provider Network Customer Network Ethernet Access Operator Domain (5) MPLS Core Customer Domain (7) Provider Domain (6) Operator Domain (5) MPLS Domain (4) MPLS Access Operator Domain (5) Maintenance Points Domains are comprised of logical entities called Maintenance Points. A maintenance point is an interface demarcation that confines CFM frames to a domain. There are two types of maintenance points: • Maintenance End Points (MEPs): a logical entity that marks the end-point of a domain • Maintenance Intermediate Points (MIPs): a logical entity configured at a port of a switch that is an intermediate point of a Maintenance Entity (ME). An ME is a point-to-point relationship between two MEPs within a single domain. MIPs are internal to a domain, not at the boundary, and respond to CFM only when triggered by linktrace and loopback messages. MIPs can be configured to snoop Continuity Check Messages (CCMs) to build a MIP CCM database. 80 | 802.1ag