Table Of Contents
Using Ethernet Operations, Administration,
and MaintenanceInformation About Using Ethernet Operations, Administration, and Maintenance
Cisco IOS Implementation of Ethernet OAM
IEEE 802.3ah Link Fault RFI Support
Ethernet Connectivity Fault Management
High Availability Features Supported by 802.3ah
NSF/SSO Support in 802.3ah OAM
How to Set Up and Configure Ethernet Operations, Administration, and Maintenance
Enabling Ethernet OAM on an Interface
Disabling and Enabling a Link Monitoring Session
Disabling a Link Monitoring Session
Enabling a Link Monitoring Session
Stopping and Starting Link Monitoring Operations
Stopping Link Monitoring Operations
Starting Link Monitoring Operations
Configuring Link Monitoring Options
Configuring Global Ethernet OAM Options Using a Template
Configuring a Port for Link Fault RFI Support
Configuration Examples for Ethernet Operations, Administration, and Maintenance
Feature Information for Using Ethernet Operations, Administration, and Maintenance
Using Ethernet Operations, Administration,
and Maintenance
First Published: November 20, 2006Last Updated: February 8, 2011Ethernet Operations, Administration, and Maintenance (OAM) is a protocol for installing, monitoring, and troubleshooting Ethernet metropolitan-area networks (MANs) and Ethernet WANs. It relies on a new, optional sublayer in the data link layer of the Open Systems Interconnection (OSI) model. The OAM features covered by this protocol are Discovery, Link Monitoring, Remote Fault Detection, Remote Loopback, and Cisco Proprietary Extensions.
The advent of Ethernet as a MAN and WAN technology has emphasized the necessity for integrated management for larger deployments. For Ethernet to extend into public MANs and WANs, it must be equipped with a new set of requirements on Ethernet's traditional operations, which had been centered on enterprise networks only. The expansion of Ethernet technology into the domain of service providers, where networks are substantially larger and more complex than enterprise networks and the user-base is wider, makes operational management of link uptime crucial.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Using Ethernet Operations, Administration, and Maintenance" section.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Information About Using Ethernet Operations, Administration, and Maintenance
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High Availability Features Supported by 802.3ah
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Configuration Examples for Ethernet Operations, Administration, and Maintenance
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Feature Information for Using Ethernet Operations, Administration, and Maintenance
Information About Using Ethernet Operations, Administration, and Maintenance
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Cisco IOS Implementation of Ethernet OAM
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IEEE 802.3ah Link Fault RFI Support
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Ethernet Connectivity Fault Management
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High Availability Features Supported by 802.3ah
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NSF/SSO Support in 802.3ah OAM
Ethernet OAM
Ethernet OAM is a protocol for installing, monitoring, and troubleshooting metro Ethernet networks and Ethernet WANs. It relies on a new, optional sublayer in the data link layer of the OSI model. Ethernet OAM can be implemented on any full-duplex point-to-point or emulated point-to-point Ethernet link. A system-wide implementation is not required; OAM can be deployed for part of a system; that is, on particular interfaces.
Normal link operation does not require Ethernet OAM. OAM frames, called OAM protocol data units (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 modest bandwidth requirements. The frame transmission rate is limited to a maximum of 10 frames per second; therefore, the impact of OAM on normal operations is negligible. However, when link monitoring is enabled, the CPU must poll error counters frequently. In this case, the required CPU cycles will be proportional to the number of interfaces that have to be polled.
Two major components, the OAM client and the OAM sublayer, make up Ethernet OAM. The following two sections describe these components.
OAM Client
The OAM client is responsible for establishing and managing Ethernet OAM on a link. The OAM client also 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 on the link based on local and remote state as well as configuration settings. Beyond the discovery phase (at steady state), the OAM client is responsible for managing the rules of response to OAM PDUs and managing the OAM remote loopback mode.
OAM Sublayer
The OAM sublayer presents two standard IEEE 802.3 MAC service interfaces: one facing toward the superior sublayers, which include the MAC client (or link aggregation), and the other interface facing toward the subordinate MAC control sublayer. The OAM sublayer provides a dedicated interface for passing OAM control information and OAM PDUs to and from a client.
The OAM sublayer is made up of three components: control block, multiplexer, and packet parser (p-parser). Each component is described in the following sections.
Control Block
The control block provides the interface between the OAM client and other blocks internal to the OAM sublayer. The control block incorporates the discovery process, which detects the existence and capabilities of remote OAM peers. It also includes the transmit process that governs the transmission of OAM PDUs to the multiplexer and a set of rules that govern the receipt of OAM PDUs from the p-parser.
Multiplexer
The multiplexer manages frames generated (or relayed) from the MAC client, control block, and p-parser. The multiplexer passes through frames generated by the MAC client untouched. It passes OAM PDUs generated by the control block to the subordinate sublayer; for example, the MAC sublayer. Similarly, the multiplexer passes loopback frames from the p-parser to the same subordinate sublayer when the interface is in OAM remote loopback mode.
P-Parser
The p-parser classifies frames as OAM PDUs, MAC client frames, or loopback frames and then dispatches each class to the appropriate entity. OAM PDUs are sent to the control block. MAC client frames are passed to the superior sublayer. Loopback frames are dispatched to the multiplexer.
Benefits of Ethernet OAM
Ethernet OAM provides the following benefits:
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Competitive advantage for service providers
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Standardized mechanism to monitor the health of a link and perform diagnostics
Cisco IOS Implementation of Ethernet OAM
The Cisco IOS implementation of Ethernet OAM consists of the Ethernet OAM shim and the Ethernet OAM module.
The Ethernet OAM shim is a thin layer that connects the Ethernet OAM module and the platform code. It is implemented in the platform code (driver). The shim also communicates port state and error conditions to the Ethernet OAM module via control signals.
The Ethernet OAM module, implemented within the control plane, handles the OAM client as well as control block functionality of the OAM sublayer. This module interacts with the command-line interface (CLI) and Simple Network Management Protocol (SNMP)/programmatic interface via control signals. In addition, this module interacts with the Ethernet OAM shim through OAM PDU flows.
OAM Features
The OAM features as defined by IEEE 802.3ah, Ethernet in the First Mile, are discovery, Link Monitoring, Remote Fault Detection, Remote Loopback, and Cisco Proprietary Extensions.
Discovery
Discovery is the first phase of Ethernet OAM and it identifies the devices in the network and their OAM capabilities. Discovery uses information OAM PDUs. During the discovery phase, the following information is advertised within periodic information OAM PDUs:
•
OAM mode—Conveyed to the remote OAM entity. The mode can be either active or passive and can be used to determine device functionality.
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OAM configuration (capabilities)—Advertises the capabilities of the local OAM entity. With this information a peer can determine what functions are supported and accessible; for example, loopback capability.
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OAM PDU configuration—Includes the maximum OAM PDU size for receipt and delivery. This information along with the rate limiting of 10 frames per second can be used to limit the bandwidth allocated to OAM traffic.
•
Platform identity—A combination of an organization unique identifier (OUI) and 32-bits of vendor-specific information. OUI allocation, controlled by the IEEE, is typically the first three bytes of a MAC address.
Discovery includes an optional phase in which the local station can accept or reject the configuration of the peer OAM entity. For example, a node may require that its partner support loopback capability to be accepted into the management network. These policy decisions may be implemented as vendor-specific extensions.
Link Monitoring
Link monitoring in Ethernet OAM detects and indicates link faults under a variety of conditions. Link monitoring uses the event notification OAM PDU and sends events to the remote OAM entity when there are problems detected on the link. The error events include the following:
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Error Symbol Period (error symbols per second)—The number of symbol errors that occurred during a specified period exceeded a threshold. These errors are coding symbol errors.
•
Error Frame (error frames per second)—The number of frame errors detected during a specified period exceeded a threshold.
•
Error Frame Period (error frames per n frames)—The number of frame errors within the last n frames has exceeded a threshold.
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Error Frame Seconds Summary (error seconds per m seconds)—The number of error seconds (1-second intervals with at least one frame error) within the last m seconds has exceeded a threshold.
Since IEEE 802.3ah OAM does not provide a guaranteed delivery of any OAM PDU, the event notification OAM PDU may be sent multiple times to reduce the probability of a lost notification. A sequence number is used to recognize duplicate events.
Remote Failure Indication
Faults in Ethernet connectivity that are caused by slowly deteriorating quality are difficult to detect. Ethernet OAM provides a mechanism for an OAM entity to convey these failure conditions to its peer via specific flags in the OAM PDU. The following failure conditions can be communicated:
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Link Fault—Loss of signal is detected by the receiver; for instance, the peer's laser is malfunctioning. A link fault is sent once per second in the information OAM PDU. Link fault applies only when the physical sublayer is capable of independently transmitting and receiving signals.
•
Dying Gasp—An unrecoverable condition has occurred; for example, a power failure. This type of condition is vendor specific. A notification about the condition may be sent immediately and continuously.
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Critical Event—An unspecified critical event has occurred. This type of event is vendor specific. A critical event may be sent immediately and continuously.
Remote Loopback
An OAM entity can put its remote peer into loopback mode using the loopback control OAM PDU. Loopback mode helps an administrator ensure the quality of links during installation or when troubleshooting. In loopback mode, every frame received is transmitted back on the same port except for OAM PDUs and pause frames. The periodic exchange of OAM PDUs must continue during the loopback state to maintain the OAM session.
The loopback command is acknowledged by responding with an information OAM PDU with the loopback state indicated in the state field. This acknowledgement allows an administrator, for example, to estimate if a network segment can satisfy a service-level agreement. Acknowledgement makes it possible to test delay, jitter, and throughput.
When an interface is set to the remote loopback mode the interface no longer participates in any other Layer 2 or Layer 3 protocols; for example Spanning Tree Protocol (STP) or Open Shortest Path First (OSPF). The reason is that when two connected ports are in a loopback session, no frames other than the OAM PDUs are sent to the CPU for software processing. The non-OAM PDU frames are either looped back at the MAC level or discarded at the MAC level.
From a user's perspective, an interface in loopback mode is in a link-up state.
Cisco Vendor-Specific Extensions
Ethernet OAM allows vendors to extend the protocol by allowing them to create their own type-length-value (TLV) fields.
OAM Messages
Ethernet OAM messages or OAM PDUs are standard length, untagged Ethernet frames within the normal frame length bounds of 64 to 1518 bytes. The maximum OAM PDU frame size exchanged between two peers is negotiated during the discovery phase.
OAM PDUs always have the destination address of slow protocols (0180.c200.0002) and an Ethertype of 8809. OAM PDUs do not go beyond a single hop and have a hard-set maximum transmission rate of 10 OAM PDUs per second. Some OAM PDU types may be transmitted multiple times to increase the likelihood that they will be successfully received on a deteriorating link.
Four types of OAM messages are supported:
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Information OAM PDU—A variable-length OAM PDU that is used for discovery. This OAM PDU includes local, remote, and organization-specific information.
•
Event notification OAM PDU—A variable-length OAM PDU that is used for link monitoring. This type of OAM PDU may be transmitted multiple times to increase the chance of a successful receipt; for example, in the case of high-bit errors. Event notification OAM PDUs also may include a time stamp when generated.
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Loopback control OAM PDU—An OAM PDU fixed at 64 bytes in length that is used to enable or disable the remote loopback command.
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Vendor-specific OAM PDU—A variable-length OAM PDU that allows the addition of vendor-specific extensions to OAM.
IEEE 802.3ah Link Fault RFI Support
The IEEE 802.3ah Link Fault RFI Support feature provides a per-port configurable option that moves a port into a blocking state when an OAM PDU control request packet is received with the Link Fault Status flag set. In the blocking state, the port can continue to receive OAM PDUs, detect remote link status, and automatically recover when the remote link becomes operational. When an OAM PDU is received with the Link Fault Status flag set to zero or FALSE, the port is enabled and all VLANs configured on the port are set to "forwarding."
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Note
If you configure the Ethernet OAM timeout period to be the minimum allowable value of 2 seconds, the Ethernet OAM session may be dropped briefly when the port transitions from blocked to unblocked. This action will not occur by default; the default timeout value is 5 seconds.
Before the release of the IEEE 802.3ah Link Fault RFI Support feature, when an OAM PDU control request packet was received with the Link Fault Status flag set, one of three actions was taken:
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The port was put in the error-disable state, meaning that the port did not send or receive packets, including Bridge Protocol Data Units (BPDU) packets. In the error-disable state, a link can automatically recover after the error-disable timeout period but cannot recover automatically when the remote link becomes operational.
•
A warning message was displayed or logged, and the port remained operational.
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The Link Fault Status flag was ignored.
A new keyword, error-block-interface, for the CLI command ethernet oam remote-failure action is introduced with the IEEE 802.3ah Link Fault RFI Support feature. For detailed information about this command, see the Cisco IOS Carrier Ethernet Command Reference.
Ethernet Connectivity Fault Management
Ethernet connectivity fault management (CFM) is an end-to-end per-service-instance Ethernet layer OAM protocol that includes proactive connectivity monitoring, fault verification, and fault isolation. End to end can be provider edge (PE) to PE or customer edge (CE) to CE. Per service instance means per VLAN.
For more information about Ethernet CFM, see Ethernet Connectivity Fault Management.
High Availability Features Supported by 802.3ah
In access and service provider networks using Ethernet technology, High Availability (HA) is a requirement, especially on Ethernet OAM components that manage Ethernet virtual circuit (EVC) connectivity. End-to-end connectivity status information is critical and must be maintained on a hot standby Route Processor (RP) (a standby RP that has the same software image as the active RP and supports synchronization of line card, protocol, and application state information between RPs for supported features and protocols). End-to-end connectivity status is maintained on the CE, PE, and access aggregation PE (uPE) network nodes based on information received by protocols such as Ethernet LMI, CFM, and 802.3ah. This status information is used to either stop traffic or switch to backup paths when an EVC is down. The Non-Stop Forwarding/Stateful Switchover (NSF/SSO) and In Service Software Upgrade (ISSU) support enhancements are introduced and enabled automatically during configuration of the Cisco 7600 router. Metro Ethernet clients (E-LMI, CFM, 802.3ah) maintain configuration data and dynamic data, which is learned through protocols. Every transaction involves either accessing or updating data among the various databases. If the databases are synchronized across active and standby modules, the RPs are transparent to clients.
Cisco IOS infrastructure provides various component application program interfaces (APIs) for clients that are helpful in maintaining a hot standby RP. Metro Ethernet HA clients (Ethernet LMI, HA/ISSU, CFM HA/ISSU, 802.3ah HA/ISSU) interact with these components, update the databases, and trigger necessary events to other components.
Benefits of 802.3ah HA
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Elimination of network downtime for Cisco IOS software image upgrades, resulting in higher availability
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Elimination of resource scheduling challenges associated with planned outages and late night maintenance windows
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Accelerated deployment of new services and applications and faster implementation of new features, hardware, and fixes due to the elimination of network downtime during upgrades
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Reduced operating costs due to outages while delivering higher service levels due to the elimination of network downtime during upgrades
NSF/SSO Support in 802.3ah OAM
The redundancy configurations SSO and NSF are both supported in Ethernet OAM and are automatically enabled. A switchover from an active to a standby RP occurs when the active RP fails, is removed from the networking device, or is manually taken down for maintenance. NSF interoperates with the SSO feature to minimize network downtime following a switchover. The primary function of Cisco NSF is to continue forwarding IP packets following an RP switchover.
For detailed information about the SSO feature, see the "Stateful Switchover" chapter of the Cisco IOS High Availability Configuration Guide. For detailed information about the NSF feature, see the "Cisco Nonstop Forwarding" chapter of the Cisco IOS High Availability Configuration Guide.
ISSU Support in 802.3ah OAM
ISSU allows you to perform a Cisco IOS software upgrade or downgrade without disrupting packet flow. ISSU is automatically enabled in 802.3ah. OAM performs a bulk update and a runtime update of the continuity check database to the standby RP, including adding, deleting, or updating a row. This checkpoint data requires ISSU capability to transform messages from one release to another. All the components that perform active RP to standby RP updates using messages require ISSU support.
ISSU lowers the impact that planned maintenance activities have on network availability by allowing software changes while the system is in service. For detailed information about ISSU, see the "Cisco OS In Service Software Upgrade Process" chapter of the Cisco IOS High Availability Configuration Guide.
How to Set Up and Configure Ethernet Operations, Administration, and Maintenance
•
Enabling Ethernet OAM on an Interface
•
Disabling and Enabling a Link Monitoring Session
•
Stopping and Starting Link Monitoring Operations
•
Configuring Link Monitoring Options
•
Configuring Global Ethernet OAM Options Using a Template
•
Configuring a Port for Link Fault RFI Support
Enabling Ethernet OAM on an Interface
Ethernet OAM is by default disabled on an interface.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam [max-rate oampdus | min-rate num-seconds | mode {active | passive} | timeout seconds]
5.
exit
DETAILED STEPS
Disabling and Enabling a Link Monitoring Session
Link monitoring is enabled by default when you enable Ethernet OAM. Perform these tasks to disable and enable link monitoring sessions:
•
Disabling a Link Monitoring Session
•
Enabling a Link Monitoring Session
Disabling a Link Monitoring Session
Perform this task to disable a link monitoring session.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam [max-rate oampdus | min-rate num-seconds | mode {active | passive} | timeout seconds]
5.
no ethernet oam link-monitor supported
6.
exit
DETAILED STEPS
Enabling a Link Monitoring Session
Perform this task to reenable a link monitoring session after it was previously disabled.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam link-monitor supported
5.
exit
DETAILED STEPS
Stopping and Starting Link Monitoring Operations
Link monitoring operations start automatically when Ethernet OAM is enabled on an interface. When link monitoring operations are stopped, the interface does not actively send or receive event notification OAM PDUs. The tasks in this section describe how to stop and start link monitoring operations.
•
Stopping Link Monitoring Operations
•
Starting Link Monitoring Operations
Stopping Link Monitoring Operations
Perform this task to stop link monitoring operations.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam [max-rate oampdus | min-rate num-seconds | mode {active | passive} | timeout seconds]
5.
no ethernet oam link-monitor on
6.
exit
DETAILED STEPS
Starting Link Monitoring Operations
Perform this task to start link monitoring operations.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam link-monitor on
5.
exit
DETAILED STEPS
Configuring Link Monitoring Options
Perform this optional task to specify link monitoring options. Steps 4 through 10 can be performed in any sequence.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam [max-rate oampdus | min-rate num-seconds | mode {active | passive} | timeout seconds]
5.
ethernet oam link-monitor high-threshold action error-disable-interface
6.
ethernet oam link-monitor frame {threshold {high {none | high-frames} | low low-frames} | window milliseconds}
7.
ethernet oam link-monitor frame-period {threshold {high {none | high-frames} | low low-frames} | window frames}
8.
ethernet oam link-monitor frame-seconds {threshold {high {none | high-frames} | low low-frames} | window milliseconds}
9.
ethernet oam link-monitor receive-crc {threshold {high {high-frames | none} | low low-frames} | window milliseconds}
10.
ethernet oam link-monitor transmit-crc {threshold {high {high-frames | none} | low low-frames} | window milliseconds}
11.
ethernet oam link-monitor symbol-period {threshold {high {none | high-symbols} | low low-symbols} | window symbols}
12.
exit
DETAILED STEPS
Examples
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface gigabitEthernet 3/8Router(config-if)#Router(config-if)# ethernet oamRouter(config-if)# ethernet oam link-monitor high-threshold action error-disable-interfaceRouter(config-if)# ethernet oam link-monitor frame window 399Router(config-if)# ethernet oam link-monitor frame-period threshold high 599Router(config-if)# ethernet oam link-monitor frame-seconds window 699Router(config-if)# ethernet oam link-monitor receive-crc window 99Router(config-if)# ethernet oam link-monitor transmit-crc threshold low 199Router(config-if)# ethernet oam link-monitor symbol-period threshold high 299Router(config-if)# exitRouter# show running-configBuilding configuration...Current configuration : 5613 bytes!!version 12.2!!...!!interface GigabitEthernet3/8no ip addressethernet oam link-monitor high-threshold action error-disable-interfaceethernet oam link-monitor frame window 399ethernet oam link-monitor frame-period threshold high 599ethernet oam link-monitor frame-seconds window 699ethernet oam link-monitor receive-crc window 99ethernet oam link-monitor transmit-crc threshold low 199ethernet oam link-monitor symbol-period threshold high 299ethernet oamConfiguring Global Ethernet OAM Options Using a Template
Perform this task to create a template to use for configuring a common set of options on multiple Ethernet OAM interfaces. Steps 4 through 10 are optional and can be performed in any sequence. These steps may also be repeated to configure different options.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
template template-name
4.
ethernet oam link-monitor receive-crc {threshold {high {high-frames | none} | low low-frames} | window milliseconds}
5.
ethernet oam link-monitor transmit-crc {threshold {high {high-frames | none} | low low-frames} | window milliseconds}
6.
ethernet oam link-monitor symbol-period {threshold {high {none | high-symbols} | low low-symbols} | window symbols}
7.
ethernet oam link-monitor high-threshold action error-disable-interface
8.
ethernet oam link-monitor frame {threshold {high {none | high-frames} | low low-frames} | window milliseconds}
9.
ethernet oam link-monitor frame-period {threshold {high {none | high-frames} | low low-frames} | window frames}
10.
ethernet oam link-monitor frame-seconds {threshold {high {none | high-frames} | low low-frames} | window milliseconds}
11.
exit
12.
interface type number
13.
source template template-name
14.
exit
15.
exit
16.
show running-config
DETAILED STEPS
Configuring a Port for Link Fault RFI Support
Perform this task to put a port into a blocking state when an OAM PDU control request packet is received with the Link Fault Status flag set.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
ethernet oam remote-failure {critical-event | dying-gasp | link-fault} action {error-block-interface | error-disable-interface}
5.
exit
DETAILED STEPS
Configuration Examples for Ethernet Operations, Administration, and Maintenance
The following example shows how to configure Ethernet OAM options using a template and overriding that configuration by configuring an interface. In this example, the network supports a Gigabit Ethernet interface between the customer edge device and provider edge device.
! Configure a global OAM template for both PE and CE configuration.!Router(config)# template oamRouter(config-template)# ethernet oam link-monitor symbol-period threshold low 10Router(config-template)# ethernet oam link-monitor symbol-period threshold high 100Router(config-template)# ethernet oam link-monitor frame window 100Router(config-template)# ethernet oam link-monitor frame threshold low 10Router(config-template)# ethernet oam link-monitor frame threshold high 100Router(config-template)# ethernet oam link-monitor frame-period window 100Router(config-template)# ethernet oam link-monitor frame-period threshold low 10Router(config-template)# ethernet oam link-monitor frame-period threshold high 100Router(config-template)# ethernet oam link-monitor frame-seconds window 1000Router(config-template)# ethernet oam link-monitor frame-seconds threshold low 10Router(config-template)# ethernet oam link-monitor frame-seconds threshold high 100Router(config-template)# ethernet oam link-monitor receive-crc window 100Router(config-template)# ethernet oam link-monitor receive-crc threshold high 100Router(config-template)# ethernet oam link-monitor transmit-crc window 100Router(config-template)# ethernet oam link-monitor transmit-crc threshold high 100Router(config-template)# ethernet oam remote-failure dying-gasp action error-disable-interfaceRouter(config-template)# exit!! Enable Ethernet OAM on the CE interface!Router(config)# interface gigabitethernet 4/1/1Router(config-if)# ethernet oam!! Apply the global OAM template named "oam" to the interface.!Router(config-if)# source template oam!! Configure any interface-specific link monitoring commands to override the template configuration. The following example disables the high threshold link monitoring for receive CRC errors.!Router(config-if)# ethernet oam link-monitor receive-crc threshold high none!! Enable Ethernet OAM on the PE interface!Router(config)# interface gigabitethernet 8/1/1Router(config-if)# ethernet oam!! Apply the global OAM template named "oam" to the interface.!Router(config-if)# source template oamThe following examples show how to verify various Ethernet OAM configurations and activities.
Verifying an OAM Session
The following example shows that the local OAM client, Gigabit Ethernet interface Gi6/1/1, is in session with a remote client with MAC address 0012.7fa6.a700 and OUI 00000C, which is the OUI for Cisco. The remote client is in active mode and has established capabilities for link monitoring and remote loopback for the OAM session.
Router# show ethernet oam summarySymbols: * - Master Loopback State, # - Slave Loopback StateCapability codes: L - Link Monitor, R - Remote LoopbackU - Unidirection, V - Variable RetrievalLocal RemoteInterface MAC Address OUI Mode CapabilityGi6/1/1 0012.7fa6.a700 00000C active L RVerifying OAM Discovery Status
The following example shows how to verify OAM discovery status of a local client and a remote peer:
Router# show ethernet oam discovery interface gigabitethernet6/1/1GigabitEthernet6/1/1Local client------------Administrative configurations:Mode: activeUnidirection: not supportedLink monitor: supported (on)Remote loopback: not supportedMIB retrieval: not supportedMtu size: 1500Operational status:Port status: operationalLoopback status: no loopbackPDU permission: anyPDU revision: 1Remote client-------------MAC address: 0030.96fd.6bfaVendor(oui): 0x00 0x00 0x0C (cisco)Administrative configurations:Mode: activeUnidirection: not supportedLink monitor: supportedRemote loopback: not supportedMIB retrieval: not supportedMtu size: 1500Verifying Information OAMPDU and Fault Statistics
The following example shows how to verify statistics for information OAM PDUs and local and remote faults:
Router# show ethernet oam statistics interface gigabitethernet6/1/1GigabitEthernet6/1/1Counters:---------Information OAMPDU Tx : 588806Information OAMPDU Rx : 988Unique Event Notification OAMPDU Tx : 0Unique Event Notification OAMPDU Rx : 0Duplicate Event Notification OAMPDU TX : 0Duplicate Event Notification OAMPDU RX : 0Loopback Control OAMPDU Tx : 1Loopback Control OAMPDU Rx : 0Variable Request OAMPDU Tx : 0Variable Request OAMPDU Rx : 0Variable Response OAMPDU Tx : 0Variable Response OAMPDU Rx : 0Cisco OAMPDU Tx : 4Cisco OAMPDU Rx : 0Unsupported OAMPDU Tx : 0Unsupported OAMPDU Rx : 0Frames Lost due to OAM : 0Local Faults:-------------0 Link Fault records2 Dying Gasp recordsTotal dying gasps : 4Time stamp : 00:30:39Total dying gasps : 3Time stamp : 00:32:390 Critical Event recordsRemote Faults:--------------0 Link Fault records0 Dying Gasp records0 Critical Event recordsLocal event logs:-----------------0 Errored Symbol Period records0 Errored Frame records0 Errored Frame Period records0 Errored Frame Second recordsRemote event logs:------------------0 Errored Symbol Period records0 Errored Frame records0 Errored Frame Period records0 Errored Frame Second recordsVerifying Link Monitoring Configuration and Status
The following example shows how to verify link monitoring configuration and status on the local client. The highlighted Status field in the example shows that link monitoring status is supported and enabled (on).
Router# show ethernet oam status interface gigabitethernet6/1/1GigabitEthernet6/1/1General-------Mode: activePDU max rate: 10 packets per secondPDU min rate: 1 packet per 1 secondLink timeout: 5 secondsHigh threshold action: no actionLink Monitoring---------------Status: supported (on)Symbol Period ErrorWindow: 1 million symbolsLow threshold: 1 error symbol(s)High threshold: noneFrame ErrorWindow: 10 x 100 millisecondsLow threshold: 1 error frame(s)High threshold: noneFrame Period ErrorWindow: 1 x 100,000 framesLow threshold: 1 error frame(s)High threshold: noneFrame Seconds ErrorWindow: 600 x 100 millisecondsLow threshold: 1 error second(s)High threshold: noneVerifying Status of a Remote OAM Client
The following example shows that the local client interface Gi6/1/1 is connected to a remote client. Note the values in the Mode and Capability fields.
Router# show ethernet oam summarySymbols: * - Master Loopback State, # - Slave Loopback StateCapability codes: L - Link Monitor, R - Remote LoopbackU - Unidirection, V - Variable RetrievalLocal RemoteInterface MAC Address OUI Mode CapabilityGi6/1/1 0012.7fa6.a700 00000C active L RAdditional References
Related Documents
Related Topic Document TitleEthernet CFM
"Configuring Ethernet Connectivity Fault Management in a Service Provider Network" in the Cisco IOS Carrier Ethernet Configuration Guide
Ethernet LMI
"Configuring Ethernet Local Management Interface" in the Cisco IOS Carrier Ethernet Configuration Guide
Configuring Ethernet LMI on a PE device
"Configuring Ethernet Local Management Interface at a Provider Edge" in the Cisco IOS Carrier Ethernet Configuration Guide
Carrier Ethernet commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples
Cisco IOS commands: master list of commands with complete command syntax, command mode, command history, defaults, usage guidelines, and examples
Standards
Standard TitleIEEE Draft P802.3ah/D3.3
Ethernet in the First Mile - Amendment
IETF VPLS OAM
L2VPN OAM Requirements and Framework
ITU-T
ITU-T Y.1731 OAM Mechanisms for Ethernet-Based Networks
MIBs
RFCs
RFC TitleNo new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.
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Technical Assistance
Feature Information for Using Ethernet Operations, Administration, and Maintenance
Table 1 lists the features in this module and provides links to specific configuration information.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
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Note
Table 1 lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Table 1 Feature Information for Using Ethernet Operations, Administration, and Maintenance
Feature Name Releases Feature InformationEthernet Operations, Administration, and Maintenance
12.2(33)SRA 12.2(33)SXH 12.4(15)T2
Cisco IOS XE 3.1.0SGEthernet OAM is a protocol for installing, monitoring, and troubleshooting metro Ethernet networks and Ethernet WANs. It relies on a new, optional sublayer in the data link layer of the OSI model. The OAM features covered by this protocol are Discovery, Link Monitoring, Remote Fault Detection, Remote Loopback, and Cisco Proprietary Extensions.
The following sections provide information about this feature:
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Cisco IOS Implementation of Ethernet OAM
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High Availability Features Supported by 802.3ah
The Ethernet Operations, Administration, and Maintenance feature was integrated into Cisco IOS Release 12.4(15)T.
The Ethernet Operations, Administration, and Maintenance feature was integrated into Cisco IOS Release 12.2(33)SXH.
The following commands were introduced or modified: clear ethernet oam statistics, debug ethernet oam, ethernet oam, ethernet oam link-monitor frame, ethernet oam link-monitor frame-period, ethernet oam link-monitor frame-seconds, ethernet oam link-monitor high-threshold action, ethernet oam link-monitor on, ethernet oam link-monitor receive-crc, ethernet oam link-monitor supported, ethernet oam link-monitor symbol-period, ethernet oam link-monitor transmit-crc, ethernet oam remote-loopback, ethernet oam remote-loopback (interface), show ethernet oam discovery, show ethernet oam statistics, show ethernet oam status, show ethernet oam summary, source template (eoam), template (eoam).
IEEE 802.3ah Link Fault RFI Support
12.2(33)SXI
The IEEE 802.3ah Link Fault RFI Support feature provides a per-port configurable option that moves a port into a blocking state when an OAM PDU control request packet is received with the Link Fault Status flag set. In the blocking state, the port can continue to receive OAM PDUs, detect remote link status, and automatically recover when the remote link becomes operational.
The following commands were introduced or modified: ethernet oam remote-failure action.
ISSU Support in 802.3ah OAM
12.2(33)SRD
Cisco IOS XE 3.1.0SGThe ISSU Support in 802.3ah OAM feature allows software to be upgraded or downgraded without disrupting packet flow.
In Cisco IOS Release 12.2(33)SRD, this feature was introduced on the Cisco 7600 series router.
The following sections provide information about this feature:
NSF/SSO Support in 802.3ah OAM
12.2(33)SRD
Cisco IOS XE 3.1.0SGThe NSF/SSO Support in 802.3ah OAM feature allows processes that support dual route processors in active and standby modes to continue forwarding packets following a switchover.
In Cisco IOS Release 12.2(33)SRD, this feature was introduced on the Cisco 7600 series router.
The following sections provide information about this feature:
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