Dell Force10 E300, Configuration Manual, Page: 79 / 1262

802.1ag | 79
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802.1ag
802.1ag is available only on platform:
s
Ethernet Operations, Administration, and Maintenance (OAM) is a set of tools used to install, monitor,
troubleshoot and manage Ethernet infrastructure deployments. Ethernet OAM consists of three main areas:
1. Service Layer OAM: IEEE 802.1ag Connectivity Fault Management (CFM)
2. Link Layer OAM: IEEE 802.3ah OAM
3. Ethernet Local management Interface (MEF-16 E-LMI)
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 in the OAM for Metro/Carrier Ethernet context is a 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 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 STP, LAG,
VRRP and 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.
• routing protocols choose a subset of the total network topology for forwarding, making it hard to detect
faults in links and nodes that are not included in the active routing topology. This is made more
complex when using some form of Traffic Engineering (TE) based routing.
• network and element discovery and cataloging is not clearly defined using IP troubleshooting tools.