- Index
- Preface
- Overview
- Using the Command-Line Interface
- Assigning the Switch IP Address and Default Gateway
- Configuring Cisco IOS CNS Agents
- Administering the Switch
- Configuring Switch Alarms
- Configuring SDM Templates
- Configuring Switch-Based Authentication
- Configuring IEEE 802.1x Port-Based Authentication
- Configuring Interface Characteristics
- Configuring Command Macros
- Configuring VLANs
- Configuring Private VLANs
- Configuring IEEE 802.1Q Tunneling, VLAN Mapping, and Layer 2 Protocol Tunneling
- Configuring STP
- Configuring MSTP
- Configuring Optional Spanning-Tree Features
- Configuring Resilient Ethernet Protocol
- Configuring Flex Links and the MAC Address-Table Move Update Feature
- Configuring DHCP Features and IP Source Guard
- Configuring Dynamic ARP Inspection
- Configuring IGMP Snooping and MVR
- Configuring Port-Based Traffic Control
- Configuring CDP
- Configuring LLDP and LLDP-MED
- Configuring UDLD
- Configuring SPAN and RSPAN
- Configuring RMON
- Configuring System Message Logging
- Configuring SNMP
- Configuring Embedded Event Manager
- Configuring Network Security with ACLs
- Configuring Control-Plane Security
- Configuring QoS
- Configuring EtherChannels and Link State Tracking
- Configuring IP Unicast Routing
- Configuring HSRP
- Configuring Cisco IOS IP SLAs Operations
- Configuring Enhanced Object Tracking
- Configuring Ethernet OAM, CFM, and E-LMI
- Configuring IP Multicast Routing
- Configuring MSDP
- Troubleshooting
- Configuring Online Diagnostics
- Supported MIBs
- Working with the Cisco IOS File System, Configuration Files, and Software Images
- Unsupported Commands in Cisco IOS Release 12.2(44)EY
- Understanding Ethernet CFM
- Configuring Ethernet CFM
Configuring Ethernet OAM, CFM, and E-LMI
Ethernet Operations, Administration, and Maintenance (OAM) is a protocol for installing, monitoring, and troubleshooting Ethernet networks to increase management capability within the context of the overall Ethernet infrastructure. The Cisco ME 3400E switch supports IEEE 802.1ag Connectivity Fault Management (CFM), Ethernet Local Management Interface (E-LMI), and IEEE 802.3ah Ethernet OAM discovery, link monitoring, remote fault detection, and remote loopback. It also supports IP Service Level Agreements (SLAs) for CFM. Ethernet OAM manager controls the interworking between any two of the protocols (CFM, E-LMI, and OAM).
This chapter provides information about configuring CFM, E-LMI, and the Ethernet OAM protocol.
For complete command and configuration information for CFM, see the Cisco IOS feature module at this URL:
http://www.cisco.com/en/US/products/ps6922/products_feature_guide09186a008066fcb8.html
For E-LMI configuration and commands see this URL: http://www.cisco.com/en/US/products/ps6441/products_feature_guide09186a0080690f2d.html
For complete syntax of the Ethernet OAM manager commands used in this chapter to configure CFM and E-LMI interaction, see the command reference for this release.
For complete command and configuration information for the Ethernet OAM protocol, see the Cisco IOS feature module at this URL:
http://www.cisco.com/en/US/products/ps6922/products_feature_guide09186a008067344c.html
For documentation for the CFM and Ethernet OAM commands, see this URL:
http://www.cisco.com/en/US/docs/ios/cether/command/reference/ce_book.html
This chapter contains these sections:
•Displaying Ethernet CFM Information
•Understanding the Ethernet OAM Protocol
•Setting Up and Configuring Ethernet OAM
•Displaying Ethernet OAM Protocol Information
•Displaying E-LMI and OAM Manager Information
•Ethernet CFM and Ethernet OAM Interaction
Understanding Ethernet CFM
Ethernet CFM is an end-to-end per-service-instance (per VLAN) Ethernet layer OAM protocol that includes proactive connectivity monitoring, fault verification, and fault isolation. End-to-end can be provider-edge-to provider-edge (PE-to-PE) device or customer-edge-to-customer-edge (CE-to-CE) device. Ethernet CFM, as specified by IEEE 802.1ag, is the standard for Layer 2 ping, Layer 2 traceroute, and end-to-end connectivity check of the Ethernet network.
Unlike CFM, other metro-Ethernet OAM protocols are not end-to-end technologies. For example, IEEE 802.3ah OAM is a single-hop and per-physical-wire protocol and is not end-to-end or service aware. E-LMI is confined between the user provider-edge (UPE) and the CE device and relies on CFM for reporting status of the metro-Ethernet network to the customer-edge device.
These sections contain conceptual information about Ethernet CFM:
CFM Domain
A CFM maintenance domain is a management space on a network that is owned and operated by a single entity and defined by a set of ports internal to it, but at its boundary. You assign a unique maintenance level (from 0 to 7) to define the hierarchical relationship between domains. The larger the domain, the higher the level. For example, as shown in Figure 40-1, a service-provider domain would be larger than an operator domain and might have a maintenance level of 6, while the operator domain maintenance level is 3 or 4.
As shown in Figure 40-2, domains cannot intersect or overlap because that would require management by more than one entity, which is not allowed. Domains can touch or nest (if the outer domain has a higher maintenance level than the nested domain). Nesting domains is useful when a service provider contract with one or more operators to provide Ethernet service. Each operator has its own maintenance domain and the service provider domain is a superset of the operator domains. Maintenance levels of nesting domains should be communicated among the administrating organizations. CFM exchanges messages and performs operations on a per-domain basis.
Figure 40-1 CFM Maintenance Domains

Figure 40-2 Allowed Domain Relationships

Maintenance Points
A maintenance point is a demarcation point on an interface that participates in CFM within a maintenance domain. Maintenance points drop all lower-level frames and forward all higher-level frames. There are two types of maintenance points:
•Maintenance end points (MEPs) are inward-facing points at the edge of the domain that define the boundary and confine CFM messages within these boundaries. Inward facing means that they communicate through the relay function side, not the wire side (connected to the port). A MEP sends and receives CFM frames through the relay function. It drops all CFM frames of its level or lower that come from the wire side. For CFM frames from the relay side, it processes the frames at its level and drops frames at a lower level. The MEP transparently forwards all CFM frames at a higher level, regardless of whether they are received from the relay or wire side. CFM runs at the provider maintenance level (UPE-to-UPE), specifically with inward-facing MEPs at the user network interface (UNI).

Note A UNI in the context of CFM and OAM manager is not the same as a UNI port type. The CFM UNI can be a UNI, an enhanced network interface (ENI), or a network node interface (NNI) port type. The control-plane security feature on the switch rate-limits all incoming CFM messages only on UNI and ENI port types.
•Maintenance intermediate points (MIPs) are internal to a domain, not at the boundary, and respond to CFM only when triggered by traceroute and loopback messages. They forward CFM frames received from MEPs and other MIPs, drop all CFM frames at a lower level, and forward all CFM frames at a higher level, regardless of whether they are received from the relay or wire side.
If port on which the MEP is configured is blocked by Spanning-Tree Protocol (STP), the port cannot receive or transmit CFM messages. If a port on which a MIP is configured is blocked by STP, the port cannot receive or respond to messages from the relay function side, but can receive and respond to CFM messages from the wire side.
CFM Messages
CFM uses standard Ethernet frames distinguished by EtherType or (for multicast messages) by MAC address. All CFM messages are confined to a maintenance domain and to a service-provider VLAN (S-VLAN). These CFM messages are supported:
•Continuity Check (CC) messages—multicast heartbeat messages exchanged periodically between MEPs that allow MEPs to discover other MEPs within a domain and allow MIPs to discover MEPs. CC messages are configured to a domain or VLAN.
•Loopback messages—unicast frames transmitted by a MEP at administrator request to verify connectivity to a particular maintenance point, indicating if a destination is reachable. A loopback message is similar to an Internet Control Message Protocol (ICMP) ping message.
•Traceroute messages—multicast frames transmitted by a MEP at administrator request to track the path (hop-by-hop) to a destination MEP. Traceroute messages are similar in concept to UDP traceroute messages.

Note In the Cisco ME switch, the control-plane security feature rate-limits all incoming CFM messages by applying a per port policer to them. See Chapter 33, "Configuring Control-Plane Security" for more information.
Crosscheck Function
The crosscheck function is a timer-driven post-provisioning service verification between dynamically configured MEPs (using crosscheck messages) and expected MEPs (by configuration) for a service. It verifies that all endpoints of a multipoint service are operational. The crosscheck function is performed only one time and is initiated from the command-line interface (CLI).
SNMP Traps
The MEPs generate two types of SNMP traps: CC traps and crosscheck traps. Supported CC traps are MEP up, MEP down, cross-connect (a service ID does not match the VLAN), loop, and configuration error. The crosscheck traps are service up, MEP missing (an expected MEP is down), and unknown MEP.
IP SLAs Support for CFM
The switch supports CFM with IP Service Level Agreements (SLAs), which provides the ability to gather Ethernet layer network performance metrics. Available statistical measurements for the IP SLAs CFM operation include round-trip time, jitter (interpacket delay variance), and packet loss. You can schedule multiple IP SLAs operations and use Simple Network Management Protocol (SNMP) trap notifications and syslog messages for proactive threshold violation monitoring.
For more information about IP SLAs, see Chapter 38, "Configuring Cisco IOS IP SLAs Operations."
IP SLAs integration with CFM gathers Ethernet layer statistical measurements by sending and receiving Ethernet data frames between CFM MEPs. Performance is measured between the source MEP and the destination MEP. Unlike other IP SLAs operations that provide performance metrics for only the IP layer, IP SLAs with CFM provides performance metrics for Layer 2.
You can manually configure individual Ethernet ping or jitter operations. You can also configure an IP SLAs automatic Ethernet operation that queries the CFM database for all MEPs in a given maintenance domain and VLAN. The operation then automatically creates individual Ethernet ping or jitter operations based on the discovered MEPs.
For more information about IP SLAs operation with CFM, see the IP SLAs for Metro-Ethernet feature module at this URL:
http://www.cisco.com/en/US/products/ps6922/products_feature_guide09186a00807d72f5.html
Configuring Ethernet CFM
Configuring Ethernet CFM requires preparing the network and configuring services. You can optionally configure and enable crosschecking.
•Default Ethernet CFM Configuration
•Ethernet CFM Configuration Guidelines
•Preparing the Ethernet CFM Network
•Configuring Ethernet CFM Service
•Configuring Ethernet CFM Crosscheck
•Configuring IP SLAs CFM Operation
Default Ethernet CFM Configuration
CFM is globally disabled.
CFM is enabled on all interfaces. A port can be configured as a flow point (MIP/MEP), a transparent port, or disabled (CFM disabled). By default, ports are transparent ports until configured as MEP, MIP, or disabled.
There are no MEPs or MIPs configured.
Ethernet CFM Configuration Guidelines
•CFM is not supported and cannot be configured on routed ports.
•CFM is supported on EtherChannel port channels. You can configure an EtherChannel port channel as MEP or MIP. However, CFM is not supported on individual ports that belong to an EtherChannel and you cannot add a CFM port to an EtherChannel group.
•You cannot configure CFM on VLAN interfaces.
•You cannot configure CFM on an EoMPLS port.
•CFM is not supported on private VLAN ports. The configuration is allowed, but does not take affect.
Preparing the Ethernet CFM Network
Beginning in privileged EXEC mode, follow these steps to prepare the network for Ethernet CFM:
Use the no versions of the commands to remove the configuration or return to the default configurations.
Configuring Ethernet CFM Service
Beginning in privileged EXEC mode, follow these steps to set up service for Ethernet CFM:
Use the no form of each command to remove a configuration or to return to the default settings.
Configuring Ethernet CFM Crosscheck
Beginning in privileged EXEC mode, follow these steps to configure Ethernet CFM crosscheck:
Use the no form of each command to remove a configuration or to return to the default settings.
Configuring IP SLAs CFM Operation
You can manually configure an individual IP SLAs Ethernet ping or jitter echo operation or you can configure IP SLAs Ethernet operation with endpoint discovery. You can also configure multiple operation scheduling. For accurate one-way delay statistics, the clocks on the endpoint switches must be synchronized. You can configure the endpoint switches with Network Time Protocol (NTP) so that the switches are synchronized to the same clock source.
For more information about configuring IP SLAs Ethernet operation, see the IP SLAs for Metro-Ethernet feature module at this URL:
http://www.cisco.com/en/US/products/ps6922/products_feature_guide09186a00807d72f5.html
For detailed information about configuring IP SLAs operations, see the Cisco IOS IP SLAs Configuration Guide, Release 12.4T at this URL:
http://www.cisco.com/en/US/products/ps6441/products_configuration_guide_book09186a0080707055.html
For detailed information about IP SLAs commands, see the command reference at this URL: http://www.cisco.com/en/US/products/ps6441/products_command_reference_book09186a008049739b.html
This section includes these procedures:
•Manually Configuring an IP SLAs CFM Probe or Jitter Operation
•Configuring an IP SLAs Operation with Endpoint Discovery
Manually Configuring an IP SLAs CFM Probe or Jitter Operation
Beginning in privileged EXEC mode, follow these steps to manually configure an IP SLAs Ethernet echo (ping) or jitter operation:
To remove an IP SLAs operation, enter the no ip sla operation-number global configuration command.
Configuring an IP SLAs Operation with Endpoint Discovery
Beginning in privileged EXEC mode, follow these steps to use IP SLAs to automatically discover the CFM endpoints for a domain and VLAN ID. You can configure ping or jitter operations to the discovered endpoints.
To remove an IP SLAs operation, enter the no ip sla operation-number global configuration command.
Displaying Ethernet CFM Information
You can use the privileged EXEC commands in Table 40-1 to display Ethernet CFM information.
You can use the privileged EXEC commands in Table 40-2 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.
•The OAM sublayer presents two standard IEEE 802.3 MAC service interfaces facing the superior and inferior MAC sublayers. It provides a dedicated interface for the OAM client to pass OAM control information and PDUs to and from the client. It includes these components:
–The control block provides the interface between the OAM client and other OAM sublayer internal blocks.
–The multiplexer manages frames from the MAC client, the control block, and the parser and passes OAM PDUs from the control block and loopback frames from the parser to the subordinate layer.
–The parser classifies frames as OAM PDUs, MAC client frames, or loopback frames and sends them to the appropriate entity: OAM PDUs to the control block, MAC client frames to the superior sublayer, and loopback frames to the multiplexer.
OAM Features
These OAM features are defined by IEEE 802.3ah:
•Discovery identifies devices in the network and their OAM capabilities. It uses periodic OAM PDUs to advertise OAM mode, configuration, and capabilities; PDU configuration; and platform identity. An optional phase allows the local station to accept or reject the configuration of the peer OAM entity.
•Link monitoring detects and indicates link faults under a variety of conditions and uses the event notification OAM PDU to notify the remote OAM device when it detects problems on the link. Error events include when the number of symbol errors, the number of frame errors, the number of frame errors within a specified number of frames, or the number of error seconds within a specified period exceed a configured threshold.
•Remote failure indication conveys a slowly deteriorating quality of an OAM entity to its peers by communicating these conditions: Link Fault means a loss of signal, Dying Gasp means an unrecoverable condition, and Critical Event means an unspecified vendor-specific critical event. The switch can receive and process but not generate Link Fault or Critical Event OAM PDUs. It can generate Dying Gasp OAM PDUs to show when Ethernet OAM is disabled, the interface is shut down, the interface enters the error-disabled state, or the switch is reloading. It also supports Dying Gasp PDUs based on loss of power.
•Remote loopback mode to ensure link quality with a remote peer during installation or troubleshooting. In this mode, when the switch receives a frame that is not an OAM PDU or a pause frame, it sends it back on the same port. The link appears to the user to be in the up state. You can use the returned loopback acknowledgement to test delay, jitter, and throughput.

Note Another way to test connectivity, to ensure that a remote device is reachable, is to configure Ethernet loopback. See the "Enabling Ethernet Loopback" section.
OAM Messages
Ethernet OAM messages or PDUs are standard length, untagged Ethernet frames between 64 and 1518 bytes. They do not go beyond a single hop and have a maximum transmission rate of 10 OAM PDUs per second. Message types are information, event notification, loopback control, or vendor-specific OAM PDUs.
Setting Up and Configuring Ethernet OAM
•Default Ethernet OAM Configuration
•Ethernet OAM Configuration Guidelines
•Enabling Ethernet OAM on an Interface
•Enabling Ethernet OAM Remote Loopback
•Configuring Ethernet OAM Link Monitoring
•Configuring Ethernet OAM Remote Failure Indications
•Configuring Ethernet OAM Templates
Default Ethernet OAM Configuration
Ethernet OAM is disabled on all interfaces.
When Ethernet OAM is enabled on an interface, link monitoring is automatically turned on.
Remote loopback is disabled.
No Ethernet OAM templates are configured.
Ethernet OAM Configuration Guidelines
•The switch does not support monitoring of egress frames sent with cyclic redundancy code (CDC) errors. The ethernet oam link-monitor transmit crc interface-configuration or template-configuration commands are visible but are not supported on the switch. The commands are accepted, but are not applied to an interface.
•For a remote failure indication, the switch does not generate Link Fault or Critical Event OAM PDUs. However, if these PDUs are received from a link partner, they are processed. The switch supports generating and receiving Dying Gasp OAM PDUs when Ethernet OAM is disabled, the interface is shut down, the interface enters the error-disabled state, or the switch is reloading. The switch can also generate and receive Dying Gasp PDUs based on loss of power. The PDU includes a reason code to indicate why it was sent.
•The switch does not support Ethernet OAM on ports that belong to an EtherChannel.
Enabling Ethernet OAM on an Interface
Beginning in privileged EXEC mode, follow these steps to enable Ethernet OAM on an interface:
Enter the no ethernet oam interface configuration command to disable Ethernet OAM on the interface.
Enabling Ethernet OAM Remote Loopback
You must enable Ethernet OAM remote loopback on an interface for the local OAM client to initiate OAM remote loopback operations. Changing this setting causes the local OAM client to exchange configuration information with its remote peer. Remote loopback is disabled by default.
Remote loopback has these limitations:
•Internet Group Management Protocol (IGMP) packets are not looped back.
•You cannot configure Ethernet OAM remote loopback on ISL ports or ports that belong to an EtherChannel.
•If dynamic ARP inspection is enabled, ARP or reverse ARP packets are not looped or dropped.
Beginning in privileged EXEC mode, follow these steps to enable Ethernet OAM remote loopback on an interface:
Use the no ethernet oam remote-loopback {supported | timeout} interface configuration command to disable remote loopback support or remove the timeout setting.
Configuring Ethernet OAM Link Monitoring
You can configure high and low thresholds for link-monitoring features. If no high threshold is configured, the default is none —no high threshold is set. If you do not set a low threshold, it defaults to a value lower than the high threshold.
Beginning in privileged EXEC mode, follow these steps to configure Ethernet OAM link monitoring on an interface:
The ethernet oam link-monitor transmit-crc {threshold {high {high-frames | none} | low {low-frames}} | window milliseconds} command is visible on the switch and you are allowed to enter it, but it is not supported.Enter the no form of the commands to disable the configuration. Use the no form of each command to disable the threshold setting.
Configuring Ethernet OAM Remote Failure Indications
You can configure an error-disable action to occur on an interface if one of the high thresholds is exceeded, if the remote link goes down, if the remote device is rebooted, or if the remote device disables Ethernet OAM on the interface.
Beginning in privileged EXEC mode, follow these steps to enable Ethernet OAM remote-failure indication actions on an interface:
The switch does not generate Link Fault or Critical Event OAM PDUs. However, if these PDUs are received from a link partner, they are processed. The switch supports sending and receiving Dying Gasp OAM PDUs with reason codes when Ethernet OAM is disabled, the interface is shut down, the interface enters the error-disabled state, or the switch is reloading. It can also respond to and generate, Dying Gasp PDUs based on loss of power. Enter the no ethernet remote-failure {critical-event | dying-gasp | link-fault} action command to disable the remote failure indication action.
Configuring Ethernet OAM Templates
You can create a template for configuring a common set of options on multiple Ethernet OAM interfaces. The template can be configured to monitor frame errors, frame-period errors, frame-second errors, received CRS errors, and symbol-period errors and thresholds. You can also set the template to put the interface in error-disabled state if any high thresholds are exceeded. These steps are optional and can be performed in any sequence or repeated to configure different options.
Beginning in privileged EXEC mode, follow these steps to configure an Ethernet OAM template and to associate it with an interface:
The switch does not support monitoring egress frames with CRC errors. The ethernet oam link-monitor transmit-crc {threshold {high {high-frames | none} | low {low-frames}} | window milliseconds} command is visible on the switch and you can enter it, but it is not supported. Use the no form of each command to remove the option from the template. Use the no source-template template-name to remove the source template association.
Displaying Ethernet OAM Protocol Information
You can use the privileged EXEC commands in Table 40-3 to display Ethernet OAM protocol information.
Enabling Ethernet Loopback
In addition to Ethernet OAM remote loopback (see the "Enabling Ethernet OAM Remote Loopback" section), you can alternately use the ethernet loopback facility supported interface configuration command to configure per-port loopbacks for testing connectivity across multiple switches. A facility loopback puts the port into a loopback state where the link is up but the line protocol is down for regular traffic. The switch loops back all received traffic.
By default, no loopbacks are configured.
Ethernet loopback has these characteristics:
•You can configure Ethernet loopback only on physical ports; not on VLANs or port channels.
•You can configure one loopback per port and a maximum of two loopbacks on the switch.
•A port event, such as a shutdown or change from a switchport to a routed port, causes the port to end the loopback.
•You cannot configure SPAN and loopback on the switch at the same time. If you try to configure SPAN on any port while loopback is configured, you receive an error message.
•If a port is a Flex Link port or belongs to an EtherChannel, it cannot be put into a loopback state. If loopback is active, you cannot add a port to a Flex Link or EtherChannel.
•The port loopback function shares hardware resources with the VLAN mapping feature. If not enough TCAM resources are available because of VLAN-mapping configuration, when you attempt to configure loopback, you receive an error message, and the configuration is not allowed.
Beginning in privileged EXEC mode, follow these steps to enable Ethernet facility loopback on an interface:
To stop an active loopback session on an interface or to stop all active loopback sessions, enter the ethernet loopback stop {interface-id | all} privileged EXEC command. To remove the Ethernet facility loopback configuration, enter the no ethernet loopback interface configuration command.
This example shows how to configure an Ethernet loopback to swap the MAC source and destination addresses and never time out and to start the loopback process. You must confirm the command before loopback starts.
Switch(config)# interface gigabitethernet 0/1
Switch(config-if)# ethernet loopback facility mac-address swap timeout none supported
Switch(config-if)# end
Switch# ethernet loopback start gigabitethernet 0/1
This is an intrusive loopback.
Therefore, while you test Ethernet connectivity,
you will be unable to pass traffic across that link.
Proceed with Local Loopback? [confirm]
This is the output from the show ethernet loopback privileged EXEC command for the previous configuration:
Switch# show ethernet loopback
=====================================
Loopback Session 0 : Interface Gi0/1
Direction : facility
Type : port
Status : configured
MAC Mode : swap
Time out : none.
Understanding E-LMI
Ethernet Local Management Interface (E-LMI) is a protocol between the customer-edge (CE) device and the provider-edge (PE) device. It runs only on the PE-to-CE UNI link and notifies the CE device of connectivity status and configuration parameters of Ethernet services available on the CE port. E-LMI interoperates with an OAM protocol, such as CFM, that runs within the provider network to collect OAM status. CFM runs at the provider maintenance level (UPE to UPE with inward-facing MEPs at the UNI). E-LMI relies on the OAM Ethernet Infrastructure to interwork with CFM for end-to-end status of Ethernet virtual connections (EVCs) across CFM domains.
OAM manager, which streamlines interaction between any two OAM protocols, handles the interaction between CFM and E-LMI. This interaction is unidirectional, running only from OAM manager to E-LMI on the UPE side of the switch. Information is exchanged either as a result of a request from E-LMI or triggered by OAM when it received notification of a change from the OAM protocol. This type of information is relayed:
•EVC name and availability status
•Remote UNI name and status
•Remote UNI counts
You can configure Ethernet virtual connections (EVCs), service VLANs, UNI ids (for each CE-to-PE link), and UNI count and attributes. You need to configure CFM to notify the OAM manager of any change to the number of active UNIs and or the remote UNI ID for a given S-VLAN domain.
You can configure the switch as either the customer-edge device or the provider-edge device.
E-LMI Interaction with OAM Manager
No interactions are required between E-LMI and OAM manager on the CE side. On the UPE side, OAM manager defines an abstraction layer that relays data collected from OAM protocols (in this case CFM) running within the metro network to the E-LMI switch. The information flow is unidirectional (from OAM manager to the E-LMI) but is triggered in one of two ways:
•Synchronous data flow triggered by a request from the E-LMI
•Asynchronous data flow triggered by OAM manager when it receives notification from CFM that the number of remote UNIs has changed
This data includes:
•EVC name and availability status (active, not active, partially active, or not defined)
•Remote UNI name and status (up, disconnected, administratively down, excessive FCS failures, or not reachable)
•Remote UNI counts (the total number of expected UNIs and the actual number of active UNIs)
The asynchronous update is triggered only when the number of active UNIs has changed.
CFM Interaction with OAM Manager
When there is a change in the number of active UNIs or remote UNI ID for a given S-VLAN or domain, CFM asynchronously notifies the OAM manager. A change in the number of UNIs might (or might not) cause a change in EVC status. OAM manager calculates EVC status given the number of active UNIs and the total number of associated UNIs.

Note If crosscheck is disabled, no SNMP traps are sent when there is a change in the number of UNIs.
Configuring E-LMI
For E-LMI to work with CFM, you configure Ethernet virtual connections (EVCs), Ethernet service instances (EFPs), and E-LMI customer VLAN mapping. Most of the configuration occurs on the PE switch on the interfaces connected to the CE device. On the CE switch, you only need to enable E-LMI on the connecting interface. Note that you must configure some OAM parameters, for example, EVC definitions, on PE devices on both sides of a metro network.
This section includes this information:
•E-LMI and OAM Manager Configuration Guidelines
•Ethernet OAM Manager Configuration Example
Default E-LMI Configuration
Ethernet LMI is globally disabled by default. When enabled, the switch is in provider-edge (PE) mode by default.
When you globally enable E-LMI by entering the ethernet lmi global global configuration command, it is automatically enabled on all interfaces. You can also enable or disable E-LMI per interface to override the global configuration. The E-LMI command that is given last is the command that has precedence.
There are no EVCs, EFP service instances, or UNIs defined.
UNI bundling service is bundling with multiplexing.
E-LMI and OAM Manager Configuration Guidelines
OAM manager is an infrastructural element and requires two interworking OAM protocols, in this case CFM and E-LMI. For OAM to operate, the PE side of the connection must be running CFM and E-LMI.
•E-LMI is not supported on routed ports, EtherChannel port channels or ports that belong to an EtherChannel, private VLAN ports, IEEE 802.1Q tunnel ports.
•You cannot configure E-LMI on VLAN interfaces.
•When you enable E-LMI globally or on an interface, the switch is in PE mode by default, You must enter the ethernet lmi ce global configuration command to enable the switch or interface in customer-edge mode.
•When the switch is configured as a CE device, the service instance and ethernet uni interface commands are visible but not supported.
Configuring the OAM Manager
Beginning in privileged EXEC mode, follow these steps to configure OAM manager on a PE switch:
Use the no forms of the commands to delete an EVC, EFP, or UNI ID, or to return to default configurations.

Note If you configure, change, or remove a UNI service type, EVC, EFP, or CE-VLAN configuration, all configurations are checked to make sure that the configurations match (UNI service type with EVC or EFP and CE-VLAN configuration). The configuration is rejected if the configurations do not match.
Enabling E-LMI
You can enable E-LMI globally or on an interface and you can configure the switch as a PE or a CE device. Beginning in privileged EXEC mode, follow these steps to enable for E-LMI on the switch or on an interface. Note that the order of the global and interface commands determines the configuration. The command that is entered last has precedence.
Use the no ethernet lmi global configuration command to globally disable E-LMI. Use the no form of the ethernet lmi interface configuration command with keywords to disable E-LMI on the interface or to return the timers to the default settings.
Use the show ethernet lmi commands to display information that was sent to the CE from the status request poll. Use the show ethernet service commands to show current status on the device.
Ethernet OAM Manager Configuration Example
This is a simple example of configuring CFM and E-LMI with OAM manager on a PE device and on a CE device. You can configure the switch as either the PE device or the CE device.
Provider-Edge Device Configuration
This example shows a sample configuration of OAM manager, CFM, and E-LMI on the PE device:
Switch# config t
Switch(config)# ethernet cfm domain Top level 7
Switch(config)# ethernet cfm domain Provider level 4
Switch(config-ether-cfm)# service customer_1 vlan 101
Switch(config-ether-cfm)# mep crosscheck mpid 404 vlan 101
Switch(config-ether-cfm)# exit
Switch(config)# ethernet cfm domain Operator_level 2
Switch(config-ether-cfm)# service operator_1 vlan 101
Switch(config-ether-cfm)# exit
Switch(config)# ethernet cfm enable
Switch(config)# ethernet evc test1
Switch(config-evc)# oam protocol cfm svlan 101 domain Provider
Switch(config-evc)# exit
Switch(config)# ethernet evc 101
Switch(config-evc)# uni count 3
Switch(config-evc)# oam protocol cfm svlan 101 domain Operator
Switch(config-evc)# exit
Switch(config)# ethernet lmi global
Switch(config)# interface gigabitethernet 1/0/2
Switch(config-if)# ethernet cfm mip level 7
Switch(config-if)# ethernet cfm mep level 4 mpid 200 vlan 200
Switch(config-if)# service instance 101 ethernet test1
Switch(config-if-srv)# ethernet lmi ce-vlan map 101
Switch(config-if-srv)# exit
Switch(config-if)# exit
Switch(config)# ethernet cfm cc enable level 2-4 vlan 101
Switch(config)# exit
Customer-Edge Device Configuration
This example shows the commands necessary to configure E-LMI on the CE device. The switch can be configured as the CE device. The example enables E-LMI globally, but you can also enable it only on a specific interface. However, if you do not enter the ethernet lmi ce global configuration command, the interface will be in PE mode by default.
Switch# config t
Switch(config)# ethernet lmi global
Switch(config)# ethernet lmi ce
Switch(config)# exit

Note For E-LMI to work, any VLANs used on the PE device must also be created on the CE device. Create a VLAN by entering the vlan vlan-id global configuration command on the CE device, where the vlan-ids match those on the PE device and configure these VLANs as allowed VLANs by entering the switchport trunk allowed vlan vlan-ids interface configuration command. Allowed VLANs can receive and send traffic on the interface in tagged format when in trunking mode.
Displaying E-LMI and OAM Manager Information
You can use the privileged EXEC commands in Table 40-4 to display E-LMI or OAM manager information.
Ethernet CFM and Ethernet OAM Interaction
You can also configure the OAM Manager infrastructure for interaction between CFM and Ethernet OAM. When the Ethernet OAM Protocol is running on an interface that has CFM MEPs configured, Ethernet OAM informs CFM of the state of the interface. Interaction is unidirectional from the Ethernet OAM to the CFM Protocol, and the only information exchanged is the user network interface port status.
The Ethernet OAM Protocol notifies CFM when these conditions occur:
•Error thresholds are crossed at the local interface.
CFM responds to the notification by sending a port status of Local_Excessive_Errors in the Port StatusType Length Value (TLV).
•Ethernet OAM receives an OAMPDU from the remote side showing that an error threshold is exceeded on the remote endpoint.
CFM responds to the notification by sending a port status of Remote_Excessive_Errors in the Port Status TLV.
•The local port is set into loopback mode.
CFM responds by sending a port status of Test in the Port Status TLV.
•The remote port is set into loopback mode.
CFM responds by sending a port status of Test in the Port Status TLV.
This section includes this information:
•Configuring Ethernet OAM Interaction with CFM
•Ethernet OAM and CFM Configuration Example
For more information about CFM and interaction with Ethernet OAM, see the Ethernet Connectivity Fault Management feature module at this URL:
http://www.cisco.com/en/US/products/ps6922/products_feature_guide09186a008066fcb8.html
Configuring Ethernet OAM Interaction with CFM
For Ethernet OAM to function with CFM, you must configure an Ethernet Virtual Circuit (EVC) and the OAM manager, and associate the EVC with CFM. You must use an inward facing MEP for interaction with the OAM manager.

Note If you configure, change, or remove a UNI service type, EVC, Ethernet service instance, or CE-VLAN configuration, all configurations are verified to ensure that the UNI service types match the EVC configuration and that Ethernet service instances are matched with the CE-VLAN configuration. Configurations are rejected if the pairs do not match.
Configuring the OAM Manager
Beginning in privileged EXEC mode, follow these steps to configure the OAM manager on a PE device:
Enabling Ethernet OAM
Beginning in privileged EXEC mode, follow these steps to enable Ethernet OAM on an interface.
Ethernet OAM and CFM Configuration Example
These are example configurations of the interworking between Ethernet OAM and CFM in a sample service provider network with a provider-edge switch connected to a customer edge switch at each endpoint. You must configure CFM, E-LMI, and Ethernet OAM between the customer edge and the provider edge switch.
Customer-edge switch 1 (CE1) configuration:
Switch# config t
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# port-type nni
Switch(config-if)# switchport trunk allowed vlan 10
Switch(config-if)# switchport mode trunk
Switch(config-if)# ethernet oam remote-loopback supported
Switch(config-if)# ethernet oam
Switch(config-if)# exit
Provider-edge switch 1 (PE1) configuration:
Switch# config t
Switch(config)# interface fastethernet1/0/20
Switch(config-if)# switchport trunk encapsulation dot1q
Switch(config-if)# switchport mode trunk
Switch(config-if)# ethernet cfm mip level 7
Switch(config-if)# ethernet cfm mep level 4 mpid 100 vlan 10
Switch(config-if)# ethernet uni id 2004-20
Switch(config-if)# ethernet oam remote-loopback supported
Switch(config-if)# ethernet oam
Switch(config-if)# service instance 10 ethernet BLUE
Switch(config-if-srv)# ethernet lmi ce-vlan map 10
Switch(config-if-srv)# exit
Provider-edge switch 2 (PE2) configuration:
Switch# config t
Switch(config)# interface gigabitethernet1/1/20
Switch(config-if)# switchport mode trunk
Switch(config-if)# ethernet cfm mip level 7
Switch(config-if)# ethernet cfm mep level 4 mpid 101 vlan 10
Switch(config-if)# ethernet uni id 2004-20
Switch(config-if)# ethernet oam remote-loopback supported
Switch(config-if)# ethernet oam
Switch(config-if)# service instance 10 ethernet BLUE
Switch(config-if-srv)# ethernet lmi ce-vlan map 10
Switch(config-if-srv)# exit
Customer-edge switch 2 (CE2) configuration:
Switch# config t
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# port-type nni
Switch(config-if)# switchport trunk allowed vlan 10
Switch(config-if)# switchport mode trunk
Switch(config-if)# ethernet oam remote-loopback supported
Switch(config-if)# ethernet oam
Switch(config-if)# exit
These are examples of the output showing provider-edge switch port status of the configuration. Port status shows as UP at both switches.
Switch PE1:
Switch# show ethernet cfm maintenance points remote
MPID Level Mac Address Vlan PortState InGressPort Age(sec) Service ID
101 * 4 0015.633f.6900 10 UP Gi1/1/1 27 blue
Switch PE2:
Switch# show ethernet cfm maintenance points remote
MPID Level Mac Address Vlan PortState InGressPort Age(sec) Service ID
100 * 4 0012.00a3.3780 10 UP Gi1/1/1 8 blue
Total Remote MEPs: 1
This example shows the outputs when you start remote loopback on CE1 (or PE1). The port state on the remote PE switch shows as Test and the remote CE switch goes into error-disable mode.
Switch# ethernet oam remote-loopback start interface gigabitEthernet 0/1
This is a intrusive loopback.
Therefore, while you test Ethernet OAM MAC connectivity,
you will be unable to pass traffic across that link.
Proceed with Remote Loopback? [confirm]
Switch PE1:
Switch# show ethernet cfm maintenance points remote
MPID Level Mac Address Vlan PortState InGressPort Age(sec) Service ID
101 * 4 0015.633f.6900 10 UP Gi1/1/1 27 blue
Switch PE2:
Switch# show ethernet cfm maintenance points remote
MPID Level Mac Address Vlan PortState InGressPort Age(sec) Service ID
100 * 4 0012.00a3.3780 10 TEST Gi1/1/1 8 blue
Total Remote MEPs: 1
In addition, if you shut down the CE1 interface that connects to PE1, the remote PE2 port will show a PortState of Down.