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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
OL-9639-06
Chapter 39 Configuring Ethernet OAM, CFM, and E-LMI
Understanding the Ethernet OAM Protocol
You can use the privileged EXEC commands in Table 39-2 to display IP SLAs Ethernet CFM
information.
Understanding the Ethernet OAM Protocol
The Ethernet OAM protocol for installing, monitoring, and troubleshooting Metro Ethernet networks
and Ethernet WANs relies on an optional sublayer in the data link layer of the OSI model. Normal link
operation does not require Ethernet OAM. You can implement Ethernet OAM on any full-duplex
point-to-point or emulated point-to-point Ethernet link for a network or part of a network (specified
interfaces).
OAM frames, called OAM protocol data units (OAM PDUs) use the slow protocol destination MAC
address 0180.c200.0002. They are intercepted by the MAC sublayer and cannot propagate beyond a
single hop within an Ethernet network. Ethernet OAM is a relatively slow protocol, with a maximum
transmission rate of 10 frames per second, resulting in minor impact to normal operations. However,
when you enable link monitoring, because the CPU must poll error counters frequently, the number of
required CPU cycles is proportional to the number of interfaces that must be polled.
Ethernet OAM has two major components:
• The OAM client establishes and manages Ethernet OAM on a link and enables and configures the
OAM sublayer. During the OAM discovery phase, the OAM client monitors OAM PDUs received
from the remote peer and enables OAM functionality. After the discovery phase, it manages the rules
of response to OAM PDUs and the OAM remote loopback mode.
show ethernet cfm maintenance-points remote
crosscheck Displays info rmation about remote maintenance points configured statically
in a crosscheck list.
show ethernet cfm traceroute-cache Displays the contents of the traceroute cache.
show platform cfm Displays platform-independent CFM information.
Table 39-1 Displaying CFM Information (continued)
Command Purpose
Tab le 39-2 Displaying IP SLAs CFM Information
Command Purpose
show ip sla configuration [entry-number] Displays configuration values including all defaults for all IP SLAs
operations or a specific operation.
show ip sla ethernet-monitor configuration
[entry-number] Displays the configuration of the IP SLAs automatic Ethernet operation.
show ip sla statistics [entry-number |
aggregated | details] Display current or aggregated operational status and statistics.