Service Manual

802.1ag

Ethernet operations, administration, and maintenance (OAM) are a set of tools used to install, monitor, troubleshoot, and

manage Ethernet infrastructure deployments. Ethernet OAM consists of three main areas:

• Service layer OAM — IEEE 802.1ag connectivity fault management (CFM)

• Link layer OAM — IEEE 802.3ah OAM

• Ethernet local management Interface — (MEF-16 E-LMI)

Topics:

• Ethernet CFM

• Maintenance Domains

• Maintenance Points

• Maintenance End Points

• Implementation Information

• Configuring the CFM

• Enable Ethernet CFM

• Creating a Maintenance Domain

• Creating a Maintenance Association

• Create Maintenance Points

• Continuity Check Messages

• Sending Loopback Messages and Responses

• Sending Linktrace Messages and Responses

• Enabling CFM SNMP Traps

• Displaying Ethernet CFM Statistics

Ethernet CFM

Ethernet CFM is an end-to-end per-service-instance Ethernet OAM scheme which enables: proactive connectivity monitoring,

fault verification, and fault isolation.

The service-instance with regard to OAM for Metro/Carrier Ethernet is a virtual local area network (VLAN). This service is sold to

an end-customer by a network service provider. Typically the service provider contracts with multiple network operators to

provide end-to-end service between customers. For end-to-end service between customer switches, connectivity must be

present across the service provider through multiple network operators.

Layer 2 Ethernet networks usually cannot be managed with IP tools such as internet control message protocol (ICMP) Ping and

IP Traceroute. Traditional IP tools often fail because:

• there are complex interactions between various Layer 2 and Layer 3 protocols such as spanning tree protocol (STP), link

aggregation group (LAG), virtual router redundancy protocol (VRRP), and electronic commerce messaging protocol (ECMP)

configurations.

• ping and traceroute are not designed to verify data connectivity in the network and within each node in the network (such

as in the switching fabric and hardware forwarding tables).

• when networks are built from different operational domains, access controls impose restrictions that cannot be overcome

at the IP level, resulting in poor fault visibility. There is a need for hierarchical domains that can be monitored and

maintained independently by each provider or operator.

802.1ag 84