Understanding The Ethernet Oam Protocol - Cisco ME 3400 Software Configuration Manual

Understanding the Ethernet OAM Protocol

Table 41-1 Displaying CFM Information (continued)
Command
show ethernet cfm maintenance-points remote
crosscheck
show ethernet cfm traceroute-cache
show platform cfm
You can use the privileged EXEC commands in
information.
Table 41-2 Displaying IP SLAs CFM Information
Command
show ip sla configuration [entry-number]
show ip sla ethernet-monitor configuration
[entry-number]
show ip sla statistics [entry-number |
aggregated | details]
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:
•
Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
41-14
Purpose
Displays information about remote maintenance points configured statically
in a crosscheck list.
Displays the contents of the traceroute cache.
Displays platform-independent CFM information.
Purpose
Displays configuration values including all defaults for all IP SLAs
operations or a specific operation.
Displays the configuration of the IP SLAs automatic Ethernet operation.
Display current or aggregated operational status and statistics.
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.
Chapter 41 Configuring Ethernet OAM, CFM, and E-LMI
Table 41-2 to display IP SLAs Ethernet CFM
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