Managing Ethernet Networks Using Operations, Administration, and Maintenance Tools
Prime Network supports three, interrelated OAM components, including:
- Connectivity Fault Management —Connectivity Fault Management (CFM) is an end-to-end per-service-instance (per VLAN) Ethernet layer OAM protocol that includes connectivity monitoring, fault verification, and fault isolation. CFM allows you to manage individual customer service instances. Ethernet Virtual Connections (EVCs) are the services that are sold to customers and are designated by service VLAN tags. CFM operates on a per-service-VLAN (or per-EVC) basis. It lets you know when an EVC fails and provides tools to isolate the failure. See Viewing Connectivity Fault Management Properties and Configuring CFM.
- Ethernet Local Management Interface—Ethernet Local Management Interface (Ethernet LMI) operates between the customer edge (CE) and the user-facing provider edge (U-PE) devices. Ethernet LMI allows you to automatically provision CEs based on EVCs and bandwidth profiles. See Viewing Ethernet LMI Properties and Configuring E-LMI.
- Link OAM —Link OAM allows you to monitor and troubleshoot a single Ethernet link. It is an optional sublayer implemented in the Data Link Layer between the Logical Link Control (LLC) and MAC sublayers of the Open Systems Interconnect (OSI) model. You can monitor a link for critical events and, if needed, put a remote device into loopback mode for link testing. Link OAM also discovers unidirectional links, which are created when one transmission direction fails. See Viewing Link OAM Properties and Configuring L-OAM.
The following topics describe how you can use the Vision client to monitor Ethernet operations, administration, and maintenance (OAM) tools. If you cannot perform an operation that is described in these topics, you may not have sufficient permissions; see Permissions for Using Ethernet OAM Tools.
Viewing Connectivity Fault Management Properties
CFM allows you to discover and verify end-to-end, Carrier Ethernet PE-to-PE or CE-to-CE paths through bridges and LANs.
CFM consists of maintenance domains. Maintenance domains are administrative regions used to manage and administer specific network segments. Maintenance domains are organized in a hierarchy. The administrator assigns a maintenance level to the domain from 0 (lowest level) to 7 (highest level); the maintenance level determines the domain’s position within the CFM hierarchy.
CFM maintenance domain boundaries are indicated by maintenance points. A maintenance point is an interface point that participates within a CFM maintenance domain. Maintenance point types include:
- Maintenance Endpoints—Maintenance endpoints (MEPs) are active CFM elements residing at the edge of a domain. MEPs can be inward or outward facing. They periodically transmit continuity check messages and expect to periodically receive similar messages from other MEPs within a domain. If requested, MEPs can also transmit traceroute and loopback messages. MEPs are responsible for keeping CFM messages within the boundaries of a maintenance domain.
- Maintenance Intermediate Points—Maintenance intermediate points (MIPs) are passive elements that catalog information received from MEPs and other MIPs. MIPs only respond to specific CFM messages such as traceroute and loopback, and they forward those messages within the maintenance domain.
Note The Vision client does not display information for CFM maintenance endpoints or maintenance intermediate points for Cisco Viking devices if errors exist in their configurations. An error in the configuration is indicated by an exclamation point (!) in the CLI output.
For example, if you enter the command show ethernet cfm local maintenance-points, a configuration error is indicated as follows:
cfm_d100/2 cfm_s100 Te0/2/0/3.110 Up MEP 2100 eb:7a:53
!
CFM uses standard Ethernet frames. CFM frames are distinguishable by EtherType and for multicast messages, by MAC address. CFM frames are sourced, terminated, processed, and relayed by bridges. Routers support only limited CFM functions.
Bridges that cannot interpret CFM messages forward them as normal data frames. All CFM messages are confined to a maintenance domain and to an S-VLAN (PE-VLAN or Provider-VLAN). CFM supports three types of messages:
- Continuity check—Multicast heartbeat messages exchanged periodically among MEPs. They allow MEPs to discover other MEPs within a domain and allow maintenance intermediate points (MIPs) to discover MEPs. Continuity check messages (CCMs) are confined to a domain and S-VLAN.
- Loopback—Unicast frames that a MEP transmits, at the request of an administrator, to verify connectivity to a particular maintenance point. A reply to a loopback message indicates whether a destination is reachable but does not allow hop-by-hop discovery of the path. A loopback message is similar in concept to an Internet Control Message Protocol (ICMP) Echo (ping) message.
- Traceroute—Multicast frames that a MEP transmits, at the request of an administrator, to track the path (hop-by-hop) to a destination MEP. They allow the transmitting node to discover vital connectivity data about the path, and allow the discovery of all MIPs along the path that belong to the same maintenance domain. For each visible MIP, traceroute messages indicate ingress action, relay action, and egress action. Traceroute messages are similar in concept to User Datagram Protocol (UDP) traceroute messages.
From the Logical Inventory tree, you can troubleshoot MEPs using CFM ping, traceroute, MEP status, and MEP cross-check status. These commands, and all CFM commands, are described in Configuring CFM.
Prime Network associates alarms with the corresponding MEP or global CFM logical inventory objects. Prime Network correlates MEP down, MEP up, MEP missing, ETH-AIS, and ETH-RDI events with root cause alarms and corresponding tickets that exist along the path between the MEP on the reporting network element and the network element hosting the remote MEP.
To view CFM properties:
Step 1 In the Vision client, double-click the required device for CFM.
Step 2 In the Inventory window, choose Logical Inventory > CFM.
Figure 19-1 shows an example of CFM in logical inventory.
Figure 19-1 CFM in Logical Inventory
Table 19-1 describes the information displayed for CFM.
Table 19-1 CFM Properties
|
|
Cache Size |
CFM traceroute cache size in number of 5.2. |
Hold Time |
Configured hold time (in minutes) that is used to indicate to the receiver the validity of traceroute and loopback messages transmitted by the device. The default value is 2.5 times the transmit interval. |
Maximum Cache Size |
Maximum CFM traceroute cache size in number of 5.2. |
CFM Version |
CFM version, such as IEEE D8.1. |
Maintenance Domains Table
|
Name |
Domain name. |
Level |
Unique level the domain is managed on. Values range from 0 to 7. |
ID |
Optional domain identifier. |
Step 3 Click the Maintenance Intermediate Points tab to view MIP information. See Figure 19-2.
Figure 19-2 CFM Maintenance Intermediate Points Tab
Table 19-2 describes the information that is displayed in the Maintenance Intermediate Points tab.
Table 19-2 CFM Maintenance Intermediate Point Properties
|
|
Interface |
Interface configured as a MIP, hyperlinked to its entry in physical inventory. |
MAC Address |
MAC address of the interface. |
Inner VLANs |
Inner VLAN identifiers. |
VLANs |
VLANs associated with the interface. |
Auto Created |
Whether or not the MIP was automatically created: True or False. |
Level |
Unique level the domain is managed on. Values range from 0 to 7. |
Step 4 To view the details of a specific maintenance domain, do one of the following:
- Choose Logical Inventory > CFM > domain.
- Double-click the required entry in the Maintenance Domains table.
Figure 19-3 shows an example of the information displayed for the maintenance domain.
Figure 19-3 CFM Maintenance Domain Properties
Table 19-3 describes the information that is displayed for CFM maintenance domains.
Table 19-3 CFM Maintenance Domain Properties
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|
Maintenance Domain Name |
Name of the domain. |
Level |
Level at which the domain is managed: 0-7. |
ID |
Optional maintenance domain identifier. |
Maintenance Associations Table
|
Name |
Name of the maintenance association. |
Association Type |
Maintenance association type. |
Direction |
Direction of the maintenance association: Up or Down. |
Continuity Check |
Whether or not the continuity check is enabled: True or False. |
Continuity Check Interval |
Interval (in seconds) for checking continuity. |
Associated Entity |
Bridge, port, or pseudowire that the maintenance association uses for CFM. Click the hyperlinked entry to view the item in inventory. |
Cross Check |
Whether or not cross checking is enabled: True or False. |
Maximum MEPs |
Maximum number of maintenance endpoints (MEPs) that can be configured on the maintenance association. |
Inner VLAN |
Inner VLAN identifier. |
Step 5 To view the properties for a maintenance association’s endpoints, do one of the following:
- Choose Logical Inventory > CFM > domain > association.
- In the Maintenance Associations table, double-click the required association.
Figure 19-4 shows the information displayed for the maintenance association endpoints.
Figure 19-4 CFM Maintenance Association - Endpoint Properties
Table 19-4 describes the information that is displayed for CFM maintenance associations and MIPs.
Table 19-4 CFM Maintenance Association Properties
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|
Maintenance Association Name |
Name of the maintenance association. |
Association Type |
Maintenance association type, such as Bridge Domain. |
Direction |
Direction of the maintenance association: Up or Down. |
Continuity Check |
Whether or not the continuity check is enabled: True or False. |
Continuity Check Interval |
Interval (in seconds) for checking continuity. |
Cross Check |
Whether or not cross checking is enabled: True or False. |
Associated Entity |
Bridge that the maintenance association uses for CFM. Click the hyperlinked entry to view the bridge in logical inventory. |
Maximum MEPs |
Maximum number of MEPs that can be configured on the maintenance association. |
Inner VLANs |
Inner VLAN identifiers. |
Maintenance End Points Table
|
ID |
Local identifier for the MEP. |
MAC Address |
MAC address that identifies the MEP. |
Interface |
Interface on which the MEP is configured, hyperlinked to the respective EFP, VSI or interface in inventory. |
Continuity Check Status |
CFM continuity check status: MEP Active, MEP Inactive, MEP Enabled, MEP Disabled, or Unknown. |
Direction |
Direction of traffic on which the MEP is defined: Up, Down, or Unknown. |
Step 6 Click the Remote Maintenance End Points tab to view the information displayed for remote MEPs. See Figure 19-5.
Figure 19-5 Remote Maintenance End Points Table
Table 19-5 describes the information presented for remote MEPs.
Table 19-5 CFM Remote Maintenance End Points Table
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|
MEP ID |
Remote MEP identifier. |
Level |
Level at which the remote MEP is managed: 0-7. |
Status |
Status of the remote MEP, such as MEP Active. |
MAC Address |
MAC address of the remote MEP. |
Local MEP ID |
Numeric identifier assigned to the local MEP. Values range from 1 to 8191. Note If the remote MEP is in Up mode, the remote MEP is not associated to the local MEP. As a result, the Local MEP ID column is empty. |
Viewing Ethernet LMI Properties
Ethernet Local Management Interface (E-LMI) is a protocol that operates between the customer edge (CE) network element and the provider edge (PE) network element. Ethernet LMI is a protocol between the CE network element and the provider edge (PE) network element. It runs only on the PE-CE UNI link and notifies the CE of connectivity status and configuration parameters of Ethernet services available on the CE port. Ethernet 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. Ethernet LMI relies on the OAM Ethernet Infrastructure (EI) to work with CFM for end-to-end status of EVCs across CFM domains. E-LMI commands are described in Configuring E-LMI.
The IOS OAM manager stream interaction between OAM protocols, and handles the interaction between CFM and E-LMI. Ethernet LMI interaction with the OAM manager is unidirectional, running only from the OAM manager to E-LMI on the U-PE side of the switch. Information is exchanged either as a result of a request from E- LMI or triggered by the OAM manager when it receives notification of a change from the OAM protocol. Information that is relayed includes the EVC name and availability status, remote UNI name and status, and remote UNI counts.
To view Ethernet LMI properties:
Step 1 In the Vision client, double-click the device configured for Ethernet LMI.
Step 2 In the Inventory window, choose Logical Inventory > Ethernet LMI.
Figure 19-6 shows an example of Ethernet LMI properties in logical inventory.
Figure 19-6 Ethernet LMI in Logical Inventory
Table 19-6 describes the information displayed for Ethernet LMI.
Table 19-6 Ethernet LMI Properties in Logical Inventory
|
|
Globally Enabled |
Whether or not Ethernet LMI is enabled globally: True or False. |
Mode |
Ethernet LMI mode: CE or PE. |
|
EVC Name |
Name of the EVC. |
EVC Type |
Type of EVC: Point-to-point or Multipoint. |
EVC Status |
EVC status: Active, Inactive, Not Defined, or Partially Active. |
Maintenance Association |
Hyperlinked entry to the maintenance association in CFM in logical inventory. For more information about maintenance associations, see Table 19-4 . |
Active Remote UNI Count |
Number of active remote UNIs. |
Configured Remote UNI Count |
Number of configured remote UNIs. |
|
Interface Name |
Hyperlinked entry to the interface in physical inventory. For more information, see Step 4 in this procedure. |
T391 |
Frequency at which the customer equipment sends status inquiries. The range is 5-30 seconds, with a default of 10 seconds. |
T392 |
Frequency at which the metro Ethernet network verifies that status enquiries have been received. The range is 5-30 seconds, with a default of 15 seconds. A value of 0 (zero) indicates the timer is disabled. |
N391 |
Frequency at which the customer equipment polls the status of the UNI and all EVCs. The range is 1-65000 seconds, with a default of 360 seconds. |
N393 |
Error count for the metro Ethernet network. The range is 1-10, with a default of 4. |
Step 3 To view device EVC properties, double-click an EVC name in the Device EVCs tab.
The Device EVC Properties window is displayed as shown in Figure 19-7.
Figure 19-7 Device EVC Properties Window
Table 19-7 describes the information displayed in the Device EVC Properties window.
Table 19-7 Device EVC Properties in Logical Inventory
|
|
EVC Name |
Name of the EVC. |
EVC Type |
Type of EVC: Point-to-point or Multipoint. |
EVC Status |
EVC status: Active, Inactive, Not Defined, or Partially Active. |
Maintenance Association |
Hyperlinked entry to the maintenance association in CFM in logical inventory. For more information about maintenance associations, see Table 19-4 . |
Active Remote UNI Count |
Number of active remote UNIs. |
Configured Remote UNI Count |
Number of configured remote UNIs. |
|
UNI Id |
UNI identifier. |
UNI Status |
Status of the UNI: Up or Down. |
LMI Link Status |
Status of the LMI link: Up or Down. |
Interface Name |
Interface on which UNI is configured. |
Is UNI Local |
Whether or not UNI is local: True or False. |
Local Interface |
Hyperlinked entry to the interface in physical inventory. |
VLAN List |
Name of the VLAN associated with the UNI interface. |
Step 4 To view properties for an Ethernet LMI interface in physical interface, click the required interface name in the ELMI Interfaces table.
Table 19-8 describes the information displayed in the UNI Properties area in physical inventory.
Table 19-8 Ethernet LMI UNI Properties in Physical Inventory
|
|
Service Multiplexing Enabled |
Whether or not the interface is configured for UNI multiplexing: True or False. |
Bundling Enabled |
Whether or not the interface is configured for UNI bundling: True or False. |
UNI Id |
UNI identifier. |
Bundling Type |
Type of bundling applied: All-to-One or None. This field appears only when a bundling type is set. |
Viewing Link OAM Properties
Link OAM is an optional sublayer implemented in the OSI Data Link Layer between the Logical Link Control and MAC sublayers. Link (802.3AH) OAM (L-OAM) can be implemented on any full-duplex point-to-point or emulated point-to-point Ethernet link.
The frames (OAM Protocol Data Units [OAMPDUs]) cannot propagate beyond a single hop within an Ethernet network and have modest bandwidth requirements (frame transmission rate is limited to a maximum of 10 frames per second).
Link OAM processes include:
- Discovery—Discovery is the first Link OAM process. During discovery, Link OAM identifies the devices at each end of the link and learns their OAM capabilities.
- Link monitoring—Link OAM link monitoring includes:
– Monitoring links and issuing notifications when error thresholds are exceeded or faults occur.
– Collecting statistics on the number of frame errors (or percent of frames that have errors) and the number of coding symbol errors.
- Remote MIB Variable Retrieval—Provides 802.3ah MIB polling and response.
- Remote Failure indication—Informs peers when a received path goes down. Because link connectivity faults caused by slowly deteriorating quality are difficult to detect, Link OAM communicates such failure conditions to its peer using OAMPDU flags. The failure conditions that can be communicated are a loss of signal in one direction on the link, an unrecoverable error (such as a power failure), or some other critical event.
- Remote Loopback—Puts the peer device in (near-end) intrusive loopback mode using the OAMPDU loopback control. Statistics can be collected during the link testing. In loopback mode, every frame received is transmitted back unchanged on the same port (except for OAMPDUs, which are needed to maintain the OAM session). Loopback mode helps ensure the quality of links during installation or troubleshooting. Loopback mode can be configured so that the service provider device can put the customer device into loopback mode, but the customer device cannot put the service provider device in loopback mode.
Prime Network supports topology discovery based on Link OAM information and enables you to view Link OAM properties. You can also configure L-OAM using the commands described in Configuring L-OAM.
For information on CFM and Ethernet LMI, see Viewing Connectivity Fault Management Properties and Viewing Ethernet LMI Properties.
To view Link OAM properties:
Step 1 In the Vision client, double-click the device configured for Link OAM.
Step 2 In the Inventory window, choose Logical Inventory > OAM.
Figure 19-8 shows an example of Link OAM properties in logical inventory.
Figure 19-8 Link OAM Properties in Logical Inventory
Table 19-9 describes the information displayed for Link OAM.
Table 19-9 Link OAM Properties in Logical Inventory
|
|
Table Types |
Type of table. In this case, it is OAM. |
|
Local Port |
Name of the OAM-supported interface, hyperlinked to the location in physical inventory. |
Local Port ID |
Local port identifier, such as FastEthernet1/0/9. |
Admin Status |
Administrative status of the interface. |
Port Status |
Status of the port. |
Remote MAC Address |
Remote client MAC address. |
Step 3 To view detailed information about an entry in the table, double-click the required entry.
The Link OAM Data Properties window is displayed as shown in Figure 19-9.
Figure 19-9 Link OAM Data Properties Window
Table 19-10 describes the information that is displayed in the Link OAM Data Properties window.
Table 19-10 Link OAM Data Properties Window
|
|
|
Local Port |
Name of the OAM-supported interface, hyperlinked to the location in physical inventory. |
Local Port ID |
Local port identifier. |
Admin Status |
Administrative status of the interface: Up or Down. |
Port Status |
Status of the port, such as Operational. |
PDU Max Rate (Frames/sec) |
Maximum transmission rate measured by the number of OAM PDUs per second; for example, 10 packets per second. |
PDU Min Rate (Seconds/frame) |
Minimum transmission rated measured by the number of seconds required for one OAM PDU; for example, 1 packet per 2 seconds. |
Link Timeout |
Number of seconds of inactivity on a link before the link is dropped. |
High Threshold Action |
Action that occurs when the high threshold for an error is exceeded. |
Link Fault Action |
Action that occurs when the signal is lost. |
Dying Gasp Action |
Action that occurs when an unrecoverable condition is encountered. |
Critical Event Action |
Action that occurs when an unspecified vendor-specific critical event occurs. |
Mode |
Mode of the interface: Active or Passive. |
Unidirection |
Status of unidirectional Ethernet on the local interface: Supported or Not supported. |
Link Monitor |
Status of link monitoring on the local interface: Supported or Not supported. |
Remote Loopback |
Status of remote loopback on the local interface: Supported or Not supported. |
Loopback Status |
Status of loopback on the local interface: Supported or No loopback. |
|
MAC Address |
MAC address for the remote client. |
Vendor |
Vendor of the remote client. |
Mode |
Mode of the remote client: Active or Passive. |
Unidirection |
Status of unidirectional Ethernet on the remote client interface: Supported or Not supported. |
Link Monitor |
Status of link monitoring on the remote client interface: Supported or Not supported. |
Remote Loopback |
Status of loopback on the remote client interface: Supported or Not supported. |
Step 4 To view Link OAM status in physical inventory, choose Physical Inventory > chassis > slot > interface.
The Link OAM administrative status is displayed as shown in Figure 19-10.
Figure 19-10 Link OAM Administrative Status in Physical Inventory
Configuring CFM
The following CFM-related commands can be launched from the inventory by right-clicking a CFM node and choosing Commands > Configuration. Your permissions determine whether you can run these commands (see Permissions for Using Ethernet OAM Tools). To find out if a device supports these commands, see the Cisco Prime Network 5.2 Supported Cisco VNEs.
|
|
Maintenance Domain > Configure CFM Maintenance Domain |
A maintenance domain is a management space for the purpose of managing and administering a network. A single entity owns and operates a domain and is defined by the set of ports internal to it and at its boundary. Each maintenance domain can contain any number of maintenance associations. Each maintenance association identifies a service that can be uniquely identified within the maintenance domain. The CFM protocol runs within a particular maintenance association. Using this command, assign a unique maintenance level to each domain and a maintenance endpoint archived hold time. Maintenance level defines the hierarchical relationship among domains and MEP Archive Hold time acts as a demarcation point on an interface that participates in CFM. |
Global Parameters > Configure CFM Global Parameters |
Enable CFM globally for a network element. Using this command you can configure the device to transmit traceroute and loopback messages with a hold-time value that indicates the validity of the messages. |
Enable > Cisco > Continuity Check > Configure CFM Continuity Check Enable > Cisco > Continuity Check > Enable CFM Continuity Check |
Enable continuity check parameters on the specified domain, service, bridge group, and bridge domain names. |
MIP > Configure CFM MIP |
The Configure CFM MIP command configures an operator-level maintenance intermediate point (MIP) for the domain-level ID. If the port on which a MIP is configured is blocked by Spanning-Tree Protocol (STP), the MIP cannot receive CFM messages or relay them toward the relay function side. The MIP can, however, receive and respond to CFM messages from the wire. A MIP has only one level associated with it, and the command-line interface (CLI) does not allow you to configure a MIP for a domain that does not exist. |
Service ID > Configure CFM Service ID |
Use the Configure CFM Service ID command to configure the CFM service ID. |
MEP > Configure CFM MEP |
Use this command to configure maintenance endpoints (MEPs), which have the following characteristics:
- Per-maintenance domain (level) and service (S-VLAN or EVC)
- At the edge of a domain, define the boundary
- Within the bounds of a maintenance domain, confine CFM messages
- When configured to do so, proactively transmit CFM continuity check messages (CCMs)
- At the request of an administrator, transmit traceroute and loopback messages
|
Enable > Cisco > SNMP Server Traps > Enable CFM SNMP Server Traps |
Enables Ethernet CFM continuity check traps and Ethernet CFM cross-check traps |
Configuring E-LMI
The following E-LMI commands can be launched from the inventory by right-clicking an E-LMI node and choosing Commands > Configuration. Your permissions determine whether you can run these commands (see Permissions for Using Ethernet OAM Tools). To find out if a device supports these commands, see the Cisco Prime Network 5.2 Supported Cisco VNEs.
|
|
Enable > Global E-LMI |
Enable Ethernet LMI globally. |
Enable On Interface |
If E-LMI is disabled globally, you can use this command to enable E-LMI on specific interfaces. |
Configure MultiPoint To MultiPoint or Point To Point EVC |
UNI count indicates the range of the Unified network interface(UNI) is 2 to 1024; the default is 2. If you enter a value of 2, you have the option to select point-to-multipoint service. If you configure a value of 3 or greater, the service is point-to-multipoint. |
Configure UNI in an Interface |
Configure Service Instance Vlan Id on Interface |
Specify the service interface ID (Per-interface Ethernet service instance identifier that does not map to a VLAN). |
Configuring L-OAM
The following Link-OAM commands can be launched from the inventory by right-clicking and L-OAM node and choosing Commands > Configuration. Your permissions determine whether you can run these commands (see Permissions for Using Ethernet OAM Tools). To find out if a device supports these commands, see the Cisco Prime Network 5.2 Supported Cisco VNEs.
|
|
Assign Template on Interface |
Assign template name |
Configure MultiPoint To MultiPoint or Point To Point EVC |
Configure OAM (L-OAM) on any full-duplex point-to-point or emulated point-to-point Ethernet link. |
Enable OAM on Interface Disable OAM on Interface |
Enable or disable OAM on the specified interface. |
Enable E-LMI On Interface |
Interface name (if E-LMI is disabled globally, you can use this command to enable E-LMI on specific interfaces) |
Configure OAM Parameter on Interface |
Configure OAM parameters, like maximum and minimum transmission rate of OAM PDU, OAM client mode and remote loopback ability on an interface. |
Start Remote Loopback |
Specify the local interface name on which the remote loopback should be started. |
Stop Remote Loopback |
Specify the local interface name on which the remote loopback should be stopped. |