- Preface
- New and Changed Interface and Hardware Component Features
- Preconfiguring Physical Interfaces
- Advanced Configuration and Modification of the Management Ethernet Interface
- Configuring Ethernet OAM
- Configuring Link Bundling
- Configuring Virtual Loopback and Null Interfaces
- Configuring 802.1Q VLAN Interfaces
- Configuring Traffic Mirroring
Interface and Hardware Component Configuration Guide for Cisco NCS 5000 Series Routers, IOS XR Release 6.3.x
- Updated:
- April 18, 2018
Chapter: Configuring Ethernet OAM
- Configuring Ethernet OAM
- Information About Configuring Ethernet OAM
- Ethernet Link OAM
- Ethernet CFM
- Maintenance Domains
- Services
- Maintenance Points
- MIP Creation
- MEP and CFM Processing Overview
- CFM Protocol Messages
- Continuity Check (IEEE 802.1ag and ITU-T Y.1731)
- Loopback (IEEE 802.1ag and ITU-T Y.1731)
- Linktrace (IEEE 802.1ag and ITU-T Y.1731)
- Configurable Logging
- EFD
- Flexible VLAN Tagging for CFM
- CFM on MC-LAG
- RG-Level CFM
- POA-Level CFM
- Supported Features for CFM on MC-LAG
- Restrictions for CFM on MC-LAG
- Restrictions for CFM Support on Subinterfaces
- How to Configure Ethernet OAM
- Configuring Ethernet CFM
- Configuring a CFM Maintenance Domain
- Configuring Services for a CFM Maintenance Domain
- Enabling and Configuring Continuity Check for a CFM Service
- Configuring Automatic MIP Creation for a CFM Service
- Configuring Cross-Check on a MEP for a CFM Service
- Configuring Other Options for a CFM Service
- Configuring CFM MEPs
- Configuring Y.1731 AIS
- Configuring AIS in a CFM Domain Service
- Configuring AIS on a CFM Interface
- Configuring EFD for a CFM Service
- Verifying the EFD Configuration
- Configuring Flexible VLAN Tagging for CFM
- Verifying the CFM Configuration
- Troubleshooting Tips
- Configuring Ethernet CFM
- Configuration Examples for Ethernet CFM
- Ethernet CFM Domain Configuration: Example
- Ethernet CFM Service Configuration: Example
- Flexible Tagging for an Ethernet CFM Service Configuration: Example
- Continuity Check for an Ethernet CFM Service Configuration: Example
- MIP Creation for an Ethernet CFM Service Configuration: Example
- Cross-check for an Ethernet CFM Service Configuration: Example
- Other Ethernet CFM Service Parameter Configuration: Example
- MEP Configuration: Example
- Ethernet CFM Show Command: Examples
- AIS for CFM Configuration: Examples
- AIS for CFM Show Commands: Examples
- show ethernet cfm interfaces ais Command: Example
- show ethernet cfm local meps Command: Examples
- show ethernet cfm local meps detail Command: Example
Configuring Ethernet
OAM
This module describes the configuration of Ethernet Operations, Administration, and Maintenance (OAM) .
Feature History for Configuring Ethernet OAM
- Configuring Ethernet OAM
- Information About Configuring Ethernet OAM
- How to Configure Ethernet OAM
- Unidirectional Link Detection Protocol
- Configuration Examples for Ethernet OAM
Configuring Ethernet OAM
This module describes the configuration of Ethernet Operations, Administration, and Maintenance (OAM) .
Feature History for Configuring Ethernet OAM
Information About Configuring Ethernet OAM
To configure Ethernet OAM, you should understand the following concepts:
Ethernet Link OAM
Ethernet as a Metro Area Network (MAN) or a Wide Area Network (WAN) technology benefits greatly from the implementation of Operations, Administration and Maintenance (OAM) features. Ethernet link OAM features allow Service Providers to monitor the quality of the connections on a MAN or WAN. Service providers can monitor specific events, . Ethernet link OAM operates on a single, physical link and it can be configured to monitor either side or both sides of that link.
Ethernet link OAM can be configured in the following ways:
-
A Link OAM profile can be configured, and this profile can be used to set the parameters for multiple interfaces.
-
Link OAM can be configured directly on an interface.
When an interface is also using a link OAM profile, specific parameters that are set in the profile can be overridden by configuring a different value directly on the interface.
An EOAM profile simplifies the process of configuring EOAM features on multiple interfaces. An Ethernet OAM profile, and all of its features, can be referenced by other interfaces, allowing other interfaces to inherit the features of that Ethernet OAM profile.
Individual Ethernet link OAM features can be configured on individual interfaces without being part of a profile. In these cases, the individually configured features always override the features in the profile.
The preferred method of configuring custom EOAM settings is to create an EOAM profile in Ethernet configuration mode and then attach it to an individual interface or to multiple interfaces.
These standard Ethernet Link OAM features are supported on the router:
Ethernet CFM
Ethernet Connectivity Fault Management (CFM) is a service-level OAM protocol that provides tools for monitoring and troubleshooting end-to-end Ethernet services per VLAN. This includes proactive connectivity monitoring, fault verification, and fault isolation. CFM uses standard Ethernet frames and can be run on any physical media that is capable of transporting Ethernet service frames. Unlike most other Ethernet protocols which are restricted to a single physical link, CFM frames can transmit across the entire end-to-end Ethernet network.
CFM is defined in two standards:
-
ITU-T Y.1731—Redefines, but maintains compatibility with the features of IEEE 802.1ag, and defines some additional features.
Ethernet CFM supports these functions of ITU-T Y.1731:
-
ETH-CC, ETH-RDI, ETH-LB, ETH-LT—These are equivalent to the corresponding features defined in IEEE 802.1ag.
Note
The Linktrace responder procedures defined in IEEE 802.1ag are used rather than the procedures defined in Y.1731; however, these are interoperable.
-
ETH-AIS—The reception of ETH-LCK messages is also supported.
Ethernet CFM is also supported on subinterfaces. CFM provides immediate update if there is any drop in the connection links between any or all of the devices connected in a network at the subinterface level. To support Ethernet CFM on subinterfaces, the interface {HundredGigE | TenGigE | GigE | Bundle-Ether} interface-path-id.subinterface command is updated to include the subinterface path ID. For more information on the configuration, see Configuring CFM MEPs section.
Note | In Cisco IOS XR Release 6.3.1, the CFM on subinterfaces is supported only on Cisco NCS 5001 and Cisco NCS 5002 Routers, and not supported on Cisco NCS 5011 Routers. |
To understand how the CFM maintenance model works, you need to understand these concepts and features:
- Maintenance Domains
- Services
- Maintenance Points
- MIP Creation
- MEP and CFM Processing Overview
- CFM Protocol Messages
- Continuity Check (IEEE 802.1ag and ITU-T Y.1731)
- Loopback (IEEE 802.1ag and ITU-T Y.1731)
- Linktrace (IEEE 802.1ag and ITU-T Y.1731)
- Configurable Logging
- EFD
- Flexible VLAN Tagging for CFM
- CFM on MC-LAG
- RG-Level CFM
- POA-Level CFM
- Supported Features for CFM on MC-LAG
- Restrictions for CFM on MC-LAG
Maintenance Domains
A maintenance domain describes a management space for the purpose of managing and administering a network. A domain is owned and operated by a single entity and defined by the set of interfaces internal to it and at its boundary, as shown in this figure.
A maintenance domain is defined by the bridge ports that are provisioned within it. Domains are assigned maintenance levels, in the range of 0 to 7, by the administrator. The level of the domain is useful in defining the hierarchical relationships of multiple domains.
CFM maintenance domains allow different organizations to use CFM in the same network, but independently. For example, consider a service provider who offers a service to a customer, and to provide that service, they use two other operators in segments of the network. In this environment, CFM can be used in the following ways:
-
The customer can use CFM between their CE devices, to verify and manage connectivity across the whole network.
-
The service provider can use CFM between their PE devices, to verify and manage the services they are providing.
-
Each operator can use CFM within their operator network, to verify and manage connectivity within their network.
Each organization uses a different CFM maintenance domain.
This figure shows an example of the different levels of maintenance domains in a network.
Note | In CFM diagrams, the conventions are that triangles represent MEPs, pointing in the direction that the MEP sends CFM frames, and circles represent MIPs. For more information about MEPs and MIPs, see the “Maintenance Points” section on page 71.  |
To ensure that the CFM frames for each domain do not interfere with each other, each domain is assigned a maintenance level, between 0 and 7. Where domains are nested, as in this example, the encompassing domain must have a higher level than the domain it encloses. In this case, the domain levels must be negotiated between the organizations involved. The maintenance level is carried in all CFM frames that relate to that domain.
CFM maintenance domains may touch or nest, but cannot intersect. This figure illustrates the supported structure for touching and nested domains, and the unsupported intersection of domains.
Services
A CFM service allows an organization to partition its CFM maintenance domain, according to the connectivity within the network. For example, if the network is divided into a number of virtual LANs (VLANs), a CFM service is created for each of these. CFM can then operate independently in each service. It is important that the CFM services match the network topology, so that CFM frames relating to one service cannot be received in a different service. For example, a service provider may use a separate CFM service for each of their customers, to verify and manage connectivity between that customer's end points.
A CFM service is always associated with the maintenance domain that it operates within, and therefore with that domain's maintenance level. All CFM frames relating to the service carry the maintenance level of the corresponding domain.
Note | CFM Services are referred to as Maintenance Associations in IEEE 802.1ag and as Maintenance Entity Groups in ITU-T Y.1731. |
Maintenance Points
A CFM Maintenance Point (MP) is an instance of a particular CFM service on a specific interface. CFM only operates on an interface if there is a CFM maintenance point on the interface; otherwise, CFM frames are forwarded transparently through the interface.
A maintenance point is always associated with a particular CFM service, and therefore with a particular maintenance domain at a particular level. Maintenance points generally only process CFM frames at the same level as their associated maintenance domain. Frames at a higher maintenance level are always forwarded transparently, while frames at a lower maintenance level are normally dropped. This helps enforce the maintenance domain hierarchy described in the “Maintenance Domains” section on page 69, and ensures that CFM frames for a particular domain cannot leak out beyond the boundary of the domain.
Maintenance End Points (MEPs)—Created at the edge of the domain. Maintenance end points (MEPs) are members of a particular service within a domain and are responsible for sourcing and sinking CFM frames. They periodically transmit continuity check messages and receive similar messages from other MEPs within their domain. They also transmit traceroute and loopback messages at the request of the administrator. MEPs are responsible for confining CFM messages within the domain.
Maintenance Intermediate Points (MIPs)—Created in the middle of the domain. Unlike MEPS, MIPs do allow CFM frames at their own level to be forwarded.
MIP Creation
Unlike MEPs, MIPs are not explicitly configured on each interface. MIPs are created automatically according to the algorithm specified in the CFM 802.1ag standard. The algorithm, in brief, operates as follows for each interface:
-
The bridge-domain or cross-connect for the interface is found, and all services associated with that bridge-domain or cross-connect are considered for MIP auto-creation.
-
The level of the highest-level MEP on the interface is found. From among the services considered above, the service in the domain with the lowest level that is higher than the highest MEP level is selected. If there are no MEPs on the interface, the service in the domain with the lowest level is selected.
-
The MIP auto-creation configuration (mip auto-create command) for the selected service is examined to determine whether a MIP should be created.
MEP and CFM Processing Overview
The boundary of a domain is an interface, rather than a bridge or host. Therefore, MEPs can be sub-divided into two categories:
-
Down MEPs—Send CFM frames from the interface where they are configured, and process CFM frames received on that interface. Down MEPs transmit AIS messages upward (toward the cross-connect).
-
Up MEPs—Send frames into the bridge relay function, as if they had been received on the interface where the MEP is configured. They process CFM frames that have been received on other interfaces, and have been switched through the bridge relay function as if they are going to be sent out of the interface where the MEP is configured. Up MEPs transmit AIS messages downward (toward the wire). However, AIS packets are only sent when there is a MIP configured on the same interface as the MEP and at the level of the MIP.
This figure illustrates the monitored areas for Down and Up MEPs.
This figure shows maintenance points at different levels. Because domains are allowed to nest but not intersect (see Figure 3), a MEP at a low level always corresponds with a MEP or MIP at a higher level. In addition, only a single MIP is allowed on any interface—this is generally created in the lowest domain that exists at the interface and that does not have a MEP.
MIPs and Up MEPs can only exist on switched (Layer 2) interfaces, because they send and receive frames from the bridge relay function. Down MEPs can be created on switched (Layer 2) or routed (Layer 3) interfaces.
MEPs continue to operate normally if the interface they are created on is blocked by the Spanning Tree Protocol (STP); that is, CFM frames at the level of the MEP continue to be sent and received, according to the direction of the MEP. MEPs never allow CFM frames at the level of the MEP to be forwarded, so the STP block is maintained.
MIPs also continue to receive CFM frames at their level if the interface is STP blocked, and can respond to any received frames. However, MIPs do not allow CFM frames at the level of the MIP to be forwarded if the interface is blocked.
CFM Protocol Messages
The CFM protocol consists of a number of different message types, with different purposes. All CFM messages use the CFM EtherType, and carry the CFM maintenance level for the domain to which they apply.
Continuity Check (IEEE 802.1ag and ITU-T Y.1731)
Continuity Check Messages (CCMs) are “heartbeat” messages exchanged periodically between all the MEPs in a service. Each MEP sends out multicast CCMs, and receives CCMs from all the other MEPs in the service—these are referred to as peer MEPs. This allows each MEP to discover its peer MEPs, and to verify that there is connectivity between them.
MIPs also receive CCMs. MIPs use the information to build a MAC learning database that is used when responding to Linktrace. For more information about Linktrace, see the “Linktrace (IEEE 802.1ag and ITU-T Y.1731)” section.
All the MEPs in a service must transmit CCMs at the same interval. IEEE 802.1ag defines 7 possible intervals that can be used:
A MEP detects a loss of connectivity with one of its peer MEPs when some number of CCMs have been missed. This occurs when sufficient time has passed during which a certain number of CCMs were expected, given the CCM interval. This number is called the loss threshold, and is usually set to 3.
The CCM intervals of 3.3ms and 10ms for the transmission of CCM messages, are not supported. For the CCM intervals of 100 ms, 1 s, 10 s, 1 min, or 10 mins, and the loss threshold value between 2 to 250, ensure that the CCM loss time does not exceed 4 mins. CFM scale is up to a maximum of 500 sessions for a CCM interval of 100ms.
CFM is supported only on interfaces which have Layer 2 transport feature enabled.
CCM messages carry a variety of information that allows different defects to be detected in the service. This information includes:
-
A configured identifier for the domain of the transmitting MEP. This is referred to as the Maintenance Domain Identifier (MDID).
-
A configured identifier for the service of the transmitting MEP. This is referred to as the Short MA Name (SMAN). Together, the MDID and the SMAN make up the Maintenance Association Identifier (MAID). The MAID must be configured identically on every MEP in the service.
-
These are restrictions on the type of MAID that are supported for sessions with time interval of less than 1 minute. The MAID supports two types of formats on offloaded MEPs: -
A configured numeric identifier for the MEP (the MEP ID). Each MEP in the service must be configured with a different MEP ID.
-
Dynamic Remote MEPs are not supported for MEPs with less than 1min interval. You must configure MEP CrossCheck for all such MEPS.
-
Sequence numbering is not supported for MEPs with less than 1 minute interval.
-
A Remote Defect Indication (RDI). Each MEP includes this in the CCMs it is sending, if it has detected a defect relating to the CCMs it is receiving. This notifies all the MEPs in the service that a defect has been detected somewhere in the service.
-
CCM Tx/Rx statistics counters are not supported for MEPs with less than1 minute intervals.
-
Sender TLV and Cisco Proprietary TLVs are not supported for MEPs with less than 1min intervals.
-
The status of the interface where the MEP is operating—for example, whether the interface is up, down, STP blocked, and so on.
Note
The status of the interface (up/down) should not be confused with the direction of any MEPs on the interface (Up MEPs/Down MEPs).
These defects can be detected from received CCMs:
-
Interval mismatch—The CCM interval in the received CCM does not match the interval that the MEP is sending CCMs.
-
Level mismatch—A MEP has received a CCM carrying a lower maintenance level than the MEPs own level.
-
Loop—A CCM is received with the source MAC address equal to the MAC address of the interface where the MEP is operating.
-
Configuration error—A CCM is received with the same MEP ID as the MEP ID configured for the receiving MEP.
-
Cross-connect—A CCM is received with an MAID that does not match the locally configured MAID. This generally indicates a VLAN misconfiguration within the network, such that CCMs from one service are leaking into a different service.
-
Peer interface down—A CCM is received that indicates the interface on the peer is down.
-
Remote defect indication—A CCM is received carrying a remote defect indication.
Note
This defect does not cause the MEP to include a remote defect indication in the CCMs that it is sending.
Out-of-sequence CCMs can also be detected by monitoring the sequence number in the received CCMs from each peer MEP. However, this is not considered a CCM defect.
Loopback (IEEE 802.1ag and ITU-T Y.1731)
Loopback Messages (LBM) and Loopback Replies (LBR) are used to verify connectivity between a local MEP and a particular remote MP. At the request of the administrator, a local MEP sends unicast LBMs to the remote MP. On receiving each LBM, the target maintenance point sends an LBR back to the originating MEP. Loopback indicates whether the destination is reachable or not—it does not allow hop-by-hop discovery of the path. It is similar in concept to an ICMP Echo (ping). Since loopback messages are destined for unicast addresses, they are forwarded like normal data traffic, while observing the maintenance levels. At each device that the loopback reaches, if the outgoing interface is known (in the bridge's forwarding database), then the frame is sent out on that interface. If the outgoing interface is not known, then the message is flooded on all interfaces.
This figure shows an example of CFM loopback message flow between a MEP and MIP.
Loopback messages can be padded with user-specified data. This allows data corruption to be detected in the network. They also carry a sequence number which allows for out-of-order frames to be detected.
Linktrace (IEEE 802.1ag and ITU-T Y.1731)
Linktrace Messages (LTM) and Linktrace Replies (LTR) are used to track the path (hop-by-hop) to a unicast destination MAC address. At the request of the operator, a local MEP sends an LTM. Each hop where there is a maintenance point sends an LTR back to the originating MEP. This allows the administrator to discover connectivity data about the path. It is similar in concept to IP traceroute, although the mechanism is different. In IP traceroute, successive probes are sent, whereas CFM Linktrace uses a single LTM which is forwarded by each MP in the path. LTMs are multicast, and carry the unicast target MAC address as data within the frame. They are intercepted at each hop where there is a maintenance point, and either retransmitted or dropped to discover the unicast path to the target MAC address.
This figure shows an example of CFM linktrace message flow between MEPs and MIPs.
The linktrace mechanism is designed to provide useful information even after a network failure. This allows it to be used to locate failures, for example after a loss of continuity is detected. To achieve this, each MP maintains a CCM Learning Database. This maps the source MAC address for each received CCM to the interface through which the CCM was received. It is similar to a typical bridge MAC learning database, except that it is based only on CCMs and it times out much more slowly—on the order of days rather than minutes.
Note | In IEEE 802.1ag, the CCM Learning Database is referred to as the MIP CCM Database. However, it applies to both MIPs and MEPs. |
In IEEE 802.1ag, when an MP receives an LTM message, it determines whether to send a reply using the following steps:
-
The target MAC address in the LTM is looked up in the bridge MAC learning table. If the MAC address is known, and therefore the egress interface is known, then an LTR is sent.
-
If the MAC address is not found in the bridge MAC learning table, then it is looked up in the CCM learning database. If it is found, then an LTR is sent.
-
If the MAC address is not found, then no LTR is sent (and the LTM is not forwarded).
If the target MAC has never been seen previously in the network, the linktrace operation will not produce any results.
Configurable Logging
CFM supports logging of various conditions to syslog. Logging can be enabled independently for each service, and when the following conditions occur:
EFD
Ethernet Fault Detection (EFD) is a mechanism that allows Ethernet OAM protocols, such as CFM, to control the “line protocol” state of an interface.
Unlike many other interface types, Ethernet interfaces do not have a line protocol, whose state is independent from that of the interface. For Ethernet interfaces, this role is handled by the physical-layer Ethernet protocol itself, and therefore if the interface is physically up, then it is available and traffic can flow.
EFD changes this to allow CFM to act as the line protocol for Ethernet interfaces. This allows CFM to control the interface state so that if a CFM defect (such as AIS or loss of continuity) is detected with an expected peer MEP, the interface can be shut down. This not only stops any traffic flowing, but also triggers actions in any higher-level protocols to route around the problem. For example, in the case of Layer 2 interfaces, the MAC table would be cleared and MSTP would reconverge. For Layer 3 interfaces, the ARP cache would be cleared and potentially the IGP would reconverge.
This figure shows CFM detection of an error on one of its sessions EFD signaling an error to the corresponding MAC layer for the interface. This triggers the MAC to go to a down state, which further triggers all higher level protocols (Layer 2 pseudowires, IP protocols, and so on) to go down and also trigger a reconvergence where possible. As soon as CFM detects there is no longer any error, it can signal to EFD and all protocols will once again go active.
Flexible VLAN Tagging for CFM
The Flexible VLAN Tagging for CFM feature ensures that CFM packets are sent with the right VLAN tags so that they are appropriately handled as a CFM packet by the remote device. When packets are received by an edge router, they are treated as either CFM packets or data packets, depending on the number of tags in the header. The system differentiates between CFM packets and data packets based on the number of tags in the packet, and forwards the packets to the appropriate paths based on the number of tags in the packet.
CFM frames are normally sent with the same VLAN tags as the corresponding customer data traffic on the interface, as defined by the configured encapsulation and tag rewrite operations. Likewise, received frames are treated as CFM frames if they have the correct number of tags as defined by the configured encapsulation and tag rewrite configuration, and are treated as data frames (that is, they are forwarded transparently) if they have more than this number of tags.
In most cases, this behavior is as desired, since the CFM frames are then treated in exactly the same way as the data traffic flowing through the same service. However, in a scenario where multiple customer VLANs are multiplexed over a single multipoint provider service (for example, N:1 bundling), a different behavior might be desirable.
This figure shows an example of a network with multiple VLANS using CFM.
This figure shows a provider's access network, where the S-VLAN tag is used as the service delimiter. PE1 faces the customer, and PE2 is at the edge of the access network facing the core. N:1 bundling is used, so the interface encapsulation matches a range of C-VLAN tags. This could potentially be the full range, resulting in all:1 bundling. There is also a use case where only a single C-VLAN is matched, but the S-VLAN is nevertheless used as the service delimiter—this is more in keeping with the IEEE model, but limits the provider to 4094 services.
CFM is used in this network with a MEP at each end of the access network, and MIPs on the boxes within the network (if it is native Ethernet). In the normal case, CFM frames are sent by the up MEP on PE1 with two VLAN tags, matching the customer data traffic. This means that at the core interfaces and at the MEP on PE2, the CFM frames are forwarded as if they were customer data traffic, since these interfaces match only on the S-VLAN tag. So, the CFM frames sent by the MEP on PE1 are not seen by any of the other MPs.
Flexible VLAN tagging changes the encapsulation for CFM frames that are sent and received at Up MEPs. Flexible VLAN tagging allows the frames to be sent from the MEP on PE1 with just the S-VLAN tag that represents the provider service. If this is done, the core interfaces will treat the frames as CFM frames and they will be seen by the MIPs and by the MEP on PE2. Likewise, the MEP on PE1 should handle received frames with only one tag, as this is what it will receive from the MEP on PE2.
To ensure that CFM packets from Up MEPs are routed to the appropriate paths successfully, tags may be set to a specific number in a domain service, using the tags command. Currently, tags can only be set to one (1).
CFM on MC-LAG
CFM on Multi-Chassis Link Aggregation Groups is supported in the following typical network environment:
-
The customer edge (CE) device is a dual-homed device that is connected to two provider edge (PE) point-of-attachment (POA) devices. However, the dual-homed device operates without awareness of connectivity to multiple PEs.
-
The two points of attachment at the PE form a redundancy group (RG), with one POA functioning as the active POA, and the other as the standby POA for the dual-homed device link.
-
As with typical failover scenarios, if a failure occurs with the active POA, the standby POA takes over to retain the dual-homed device’s connectivity to the network.
CFM on MC-LAG support can be qualified at two levels:
-
CFM for the RG level—CFM context is per redundancy group and verifies connectivity for the entire RG.
-
CFM for the POA level—CFM context is per point of attachment and verifies connectivity to a single POA.
Both levels of CFM support have certain restrictions and configuration guidelines that you must consider for successful implementation.
For more information about LAG, see the Configuring Link Bundling chapter in this guide.
RG-Level CFM
RG-level CFM is comprised of three areas of monitoring:
RG Downlink Monitoring
RG downlink monitoring uses CFM to verify connectivity between the dual-homed device and the RG.
To configure RG downlink monitoring, be sure that the following requirements are met:
End-to-End Service Monitoring
End-to-end service monitoring uses CFM to verify the end-to-end service between the dual-homed devices.
To configure end-to-end service monitoring, be sure that the following requirements are met:
POA-Level CFM
POA-level monitoing uses CFM to verify connectivity between the dual-homed device and a single POA.
To configure POA-level CFM, be sure that these requirements are met:
Supported Features for CFM on MC-LAG
CFM on MC-LAG supports these CFM features:
-
All existing IEEE 802.1ag and Y.1731 functionality is supported on an MC-LAG RG.
-
CFM maintenance points are supported on an MC-LAG interface. Maintenance points on a standby link are put into standby state.
-
Maintenance points in standby state receive CFM messages, but do not send or reply to any CFM messages.
-
When a MEP transitions from active to standby, all CCM defects and alarms are cleared.
-
Standby MEPs record remote MEP errors and timeouts, but do not report faults. This means that remote MEPs and their errors will appear in show commands, but no logs, alarms, MIB traps, or EFD are triggered and AIS messages are not sent.
-
When a MEP transitions from standby to active, any CCM defects previously detected while the MEP was in standby are reapplied and immediate actions are taken (logs, alarms, MIB traps, EFD, and so on).
Restrictions for CFM on MC-LAG
To support CFM on MC-LAG, you must consider these restrictions and requirements:
-
The CFM configuration must be the same on both the active and standby POAs.
-
The CFM state is not synchronized between the two POAs. This can lead to flapping of the interface line protocol state on POA failover if EFD is configured. Fault alarms might also be delayed if a failover occurs just after a fault has been detected.
-
POA-level CFM monitoring is not supported on a native Ethernet uplink interface.
-
Loopback, linktrace, and Y.1731 SLA operations cannot be started from a MEP in standby state.
-
Checks for configuration consistency of MEP IDs to ensure identical configuration of POAs is not supported.
-
Y.1731 SLA statistics can be split between the two POAs if a failover occurs. An external network management system would need to collect and collate these statistics from the two POAs.
Restrictions for CFM Support on Subinterfaces
-
The CFM is not supported on Cisco NCS 5011 Routers.
-
Up MEPs are not supported.
-
The CCM intervals of 3.3ms and 10ms for the transmission of CCM messages, are not supported.
-
CFM scale is up to a maximum of 500 sessions for a CCM interval of 100ms.
-
For the CCM intervals of 100 ms, 1 second, 10 second, 1 min, or 10 mins, and the loss threshold value between 2 to 250, ensure that the CCM loss time does not exceed 4 mins.
How to Configure Ethernet OAM
Configuring Ethernet CFM
To configure Ethernet CFM, perform the following tasks:
Note | CFM is not supported for the following:
|
Configuring a CFM Maintenance Domain
To configure a CFM maintenance domain, perform the following steps:
3.
domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
DETAILED STEPS
Configuring Services for a CFM Maintenance Domain
You can configure up to 32000 CFM services for a maintenance domain. To configure services for a CFM maintenance domain, perform the following steps:
3.
domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
4. service service-name {down-meps | xconnect group xconnect-group-name p2p xconnect-name}[id [icc-based icc-string umc-string] | [ [number number]
DETAILED STEPS
Enabling and Configuring Continuity Check for a CFM Service
To configure Continuity Check for a CFM service, complete the following steps:
3.
domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
4. service service-name {down-meps | xconnect group xconnect-group-name p2p xconnect-name}[id [icc-based icc-string umc-string] | [ [number number]
5.
continuity-check
interval
time [loss-threshold
threshold]
6.
continuity-check
archive
hold-time
minutes
DETAILED STEPS
Configuring Automatic MIP Creation for a CFM Service
For more information about the algorithm for creating MIPs, see the MIP Creation section.
To configure automatic MIP creation for a CFM service, complete the following steps:
3.
domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
4.
service
service-name {down-meps | xconnect
group xconnect-group-name
p2p xconnect-name}[id
[icc-basedicc-string
umc-string] |
[number
number]
DETAILED STEPS
Configuring Cross-Check on a MEP for a CFM Service
To configure cross-check on a MEP for a CFM service and specify the expected set of MEPs, complete the following steps:
3.
domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
4. service service-name {bridge group bridge-domain-group bridge-domain bridge-domain-name | down-meps | xconnect group xconnect-group-name p2p xconnect-name}[id [icc-based icc-string umc-string] | [string text] | [number number] | [vlan-id id-number] | [vpn-id oui-vpnid]]
DETAILED STEPS
Configuring Other Options for a CFM Service
To configure other options for a CFM service, complete the following steps:
3.
domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
4. service service-name {bridge group bridge-domain-group bridge-domain bridge-domain-name | down-meps | xconnect group xconnect-group-name p2p xconnect-name}[id [icc-based icc-string umc-string] | [string text] | [number number] | [vlan-id id-number] | [vpn-id oui-vpnid]]
6.
log
{ais|continuity-check errors|continuity-check mep changes|crosscheck errors|efd}
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 | configure
Example: RP/0/RP0/CPU0:router# configure | |
| Step 2 | ethernet cfm
Example: RP/0/RP0/CPU0:router# ethernet cfm |
Enters the Ethernet Connectivity Fault Management (CFM) configuration mode. |
| Step 3 | domain
domain-name
level
level-value [id [null] [dns
DNS-name] [mac
H.H.H] [string
string] ]
Example: RP/0/RP0/CPU0:router(config-cfm)# domain Domain_One level 1 id string D1 |
Creates and names a container for all domain configurations and enters the CFM domain configuration mode. The id is the maintenance domain identifier (MDID) and is used as the first part of the maintenance association identifier (MAID) in CFM frames. If the MDID is not specified, the domain name is used as the MDID by default. |
| Step 4 | service
service-name {bridge group
bridge-domain-group
bridge-domain
bridge-domain-name |
down-meps | xconnect
group xconnect-group-name
p2p xconnect-name}[id
[icc-based
icc-string
umc-string] |
[string
text] | [number
number] | [vlan-id
id-number] | [vpn-id
oui-vpnid]]
Example: RP/0/RP0/CPU0:router(config-cfm-dmn)# service Bridge_Service bridge group BD1 bridge-domain B1 |
Configures and associates a service with the domain and enters CFM domain service configuration mode. You can specify that the service is used only for down MEPs, or associate the service with a bridge domain or xconnect where MIPs and up MEPs will be created. |
| Step 5 | maximum-meps
number
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# maximum-meps 1000 |
(Optional) Configures the maximum number (2 to 8190) of MEPs across the network, which limits the number of peer MEPs recorded in the database. |
| Step 6 | log
{ais|continuity-check errors|continuity-check mep changes|crosscheck errors|efd}
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# log continuity-check errors | |
| Step 7 | end or
commit
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# commit |
|
Configuring CFM MEPs
When you configure CFM MEPs, consider these guidelines:
-
CFM is supported on Cisco NCS 5001 and Cisco NCS 5002 Series routers only.
-
Up to 672 (84 physical interfaces*8 levels) local MEPs are supported per card.
-
CFM maintenance points can be created only on physical Ethernet interfaces.
-
CFM maintenance points can be created on these interface types:
-
CFM maintenance points can be created on both Layer 2 and Layer 3 interfaces. On L3 interfaces, only down MEPs can be created.
-
Up MEPs are not supported.
2.
interface {HundredGigE | TenGigE}
interface-path-id
3.
interface {HundredGigE | TenGigE | Bundle-Ether}
interface-path-id.subinterface
5.
interface {HundredGigE | TenGigE}
interface-path-id
7.
mep domain
domain-name
service
service-name
mep-id
id-number
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 | configure
Example: RP/0/RP0/CPU0:router# configure | |||
| Step 2 | interface {HundredGigE | TenGigE}
interface-path-id
Example:
RP/0/RP0/CPU0:router(config)# interface TenGigE 0/0/0/1
|
Type of Ethernet interface on which you want to create a MEP. Enter HundredGigE or TenGigE and the physical interface or virtual interface.
| ||
| Step 3 | interface {HundredGigE | TenGigE | Bundle-Ether}
interface-path-id.subinterface
Example: RP/0/RP0/CPU0:router(config)# interface TenGigE 0/0/0/1
|
Type of Ethernet interface on which you want to create a MEP. Enter HundredGigE, TenGigE, or Bundle-Ether and the physical interface or virtual interface followed by the subinterface path ID. Naming convention is interface-path-id.subinterface. The period in front of the subinterface value is required as part of the notation. | ||
| Step 4 | vrf vrf-name
Example:
RP/0/RP0/CPU0:router(config-if)# vrf vrf_A
|
Configures a VRF instance and enters VRF configuration mode. | ||
| Step 5 | interface {HundredGigE | TenGigE}
interface-path-id
Example: RP/0/RP0/CPU0:router(config)# interface TenGigE 0/0/0/1
|
Type of Ethernet interface on which you want to create a MEP. Enter HundredGigE or TenGigE and the physical interface or virtual interface.
| ||
| Step 6 | ethernet cfm
Example: RP/0/RP0/CPU0:router(config-if)# ethernet cfm | |||
| Step 7 | mep domain
domain-name
service
service-name
mep-id
id-number
Example: RP/0/RP0/CPU0:router(config-if-cfm)# mep domain Dm1 service Sv1 mep-id 1 |
Creates a maintenance end point (MEP) on an interface and enters interface CFM MEP configuration mode. | ||
| Step 8 | cos
cos
Example: RP/0/RP0/CPU0:router(config-if-cfm-mep)# cos 7 |
(Optional) Configures the class of service (CoS) (from 0 to 7) for all CFM packets generated by the MEP on an interface. If not configured, the CoS is inherited from the Ethernet interface.
| ||
| Step 9 | end or
commit
Example: RP/0/RP0/CPU0:router(config-if-cfm-mep)# commit |
|
Configuring Y.1731 AIS
Configuring AIS in a CFM Domain Service
Use the following procedure to configure Alarm Indication Signal (AIS) transmission for a CFM domain service and configure AIS logging.
4.
service
name bridge group
name bridge-domain
name
5.
service
name
xconnect group
xconnect-group-name
p2p
xconnect-name
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 | configure
Example: RP/0/RP0/CPU0:router# configure | |
| Step 2 | ethernet cfm
Example: RP/0/RP0/CPU0:router(config)# ethernet cfm | |
| Step 3 | domain
name level
level
Example: RP/0/RP0/CPU0:router(config-cfm)# domain D1 level 1 | |
| Step 4 | service
name bridge group
name bridge-domain
name
Example: RP/0/RP0/CPU0:router(config-cfm-dmn)# service S1 bridge group BG1 bridge-domain BD2 | |
| Step 5 | service
name
xconnect group
xconnect-group-name
p2p
xconnect-name
Example: RP/0/RP0/CPU0:router(config-cfm-dmn)# service S1 bridge group BG1 bridge-domain BD2 | |
| Step 6 | ais transmission
[interval
{1s|1m}][cos
cos]
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# ais transmission interval 1m cos 7 |
Configures Alarm Indication Signal (AIS) transmission for a Connectivity Fault Management (CFM) domain service. |
| Step 7 | log ais
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# log ais |
Configures AIS logging for a Connectivity Fault Management (CFM) domain service to indicate when AIS or LCK packets are received. |
| Step 8 | end or
commit
Example: RP/0/RP0/CPU0:router(config-sla-prof-stat-cfg)# commit |
|
Configuring AIS on a CFM Interface
To configure AIS on a CFM interface, perform the following steps:
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 | configure
Example: RP/0/RP0/CPU0:router# configure | |
| Step 2 | interface gigabitethernet
interface-path-id
Example: RP/0/RP0/CPU0:router# interface TenGigE 0/0/0/2 | |
| Step 3 | ethernet cfm
Example: RP/0/RP0/CPU0:router(config)# ethernet cfm | |
| Step 4 | ais transmission up interval
1m cos
cos
Example: RP/0/RP0/CPU0:router(config-if-cfm)# ais transmission up interval 1m cos 7 |
Configures Alarm Indication Signal (AIS) transmission on a Connectivity Fault Management (CFM) interface. |
| Step 5 | end or
commit
Example: RP/0/RP0/CPU0:router(config-sla-prof-stat-cfg)# commit |
|
Configuring EFD for a CFM Service
To configure EFD for a CFM service, complete the following steps.
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 | configure
Example: RP/0/RP0/CPU0:router# configure | |
| Step 2 | ethernet cfm
Example: RP/0/RP0/CPU0:router(config)# ethernet cfm | |
| Step 3 | domain
domain-name
level
level-value
Example: RP/0/RP0/CPU0:router(config-cfm-dmn)# domain D1 level 1 |
Specifies or creates the CFM domain and enters CFM domain configuration mode. |
| Step 4 | service
service-name
down-meps
Example: RP/0/RP0/CPU0:router(config-cfm-dmn)# service S1 down-meps |
Specifies or creates the CFM service for down MEPS and enters CFM domain service configuration mode. |
| Step 5 | efd
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# efd | |
| Step 6 | log efd
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# log efd |
(Optional) Enables logging of EFD state changes on an interface. |
| Step 7 | end or
commit
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# commit |
|
Verifying the EFD Configuration
This example shows how to display all interfaces that are shut down because of Ethernet Fault Detection (EFD):
RP/0/RP0/CPU0:router# show efd interfaces Server VLAN MA ============== Interface Clients ------------------------- TenGigE0/0/0/0.0 CFM
Configuring Flexible VLAN Tagging for CFM
Use this procedure to set the number of tags in CFM packets in a CFM domain service.
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 | configure
Example: RP/0/RP0/CPU0:router# configure | |
| Step 2 | ethernet cfm
Example: RP/0/RP0/CPU0:router(config)# ethernet cfm | |
| Step 3 | domain
name level
level
Example: RP/0/RP0/CPU0:router(config-cfm)# domain D1 level 1 | |
| Step 4 | service
name bridge group
name bridge-domain
name
Example: RP/0/RP0/CPU0:router(config-cfm-dmn)# service S2 bridge group BG1 bridge-domain BD2 | |
| Step 5 | tags
number
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# tags 1 |
Specifies the number of tags in CFM packets. Currently, the only valid value is 1. |
| Step 6 | end or
commit
Example: RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# commit |
|
Verifying the CFM Configuration
To verify the CFM configuration, use one or more of the following commands:
show ethernet cfm configuration-errors [domain domain-name] [interface interface-path-id ] |
Displays information about errors that are preventing configured CFM operations from becoming active, as well as any warnings that have occurred. |
show ethernet cfm local maintenance-points domain name [service name] | interface type interface-path-id] [mep | mip] |
Note | After you configure CFM, the error message, cfmd[317]: %L2-CFM-5-CCM_ERROR_CCMS_MISSED : Some received CCMs have not been counted by the CCM error counters, may display. This error message does not have any functional impact and does not require any action from you. |
Troubleshooting Tips
To troubleshoot problems within the CFM network, perform these steps:
1. To verify connectivity to a problematic MEP, use the ping ethernet cfm command as shown in this example:
2. If the results of the ping ethernet cfm command show a problem with connectivity to the peer MEP, use the traceroute ethernet cfm command to help further isolate the location of the problem as shown in the following example:
DETAILED STEPS
| Step 1 | To verify connectivity to a problematic MEP, use the
ping ethernet
cfm command as shown in this example:
RP/0/RP0/CPU0:router# ping ethernet cfm domain D1 service S1 mep-id 16 source interface TenGigE 0/0/0/1 Type escape sequence to abort. Sending 5 CFM Loopbacks, timeout is 2 seconds - Domain foo (level 2), Service foo Source: MEP ID 1, interface TenGigE0/0/0/1 Target: 0001.0002.0003 (MEP ID 16): Running (5s) ... Success rate is 60.0 percent (3/5), round-trip min/avg/max = 1251/1349/1402 ms Out-of-sequence: 0.0 percent (0/3) Bad data: 0.0 percent (0/3) Received packet rate: 1.4 pps |
| Step 2 | If the results of the
ping ethernet
cfm command show a problem with connectivity to the peer MEP, use
the
traceroute ethernet
cfm command to help further isolate the location of the problem
as shown in the following example:
RP/0/RP0/CPU0:router# traceroute ethernet cfm domain D1 service S1 mep-id 16 source interface TenGigE 0/0/0/2 Traceroutes in domain D1 (level 4), service S1 Source: MEP-ID 1, interface TenGigE0/0/0/2 ================================================================================ Traceroute at 2009-05-18 12:09:10 to 0001.0203.0402, TTL 64, Trans ID 2: Hop Hostname/Last Ingress MAC/name Egress MAC/Name Relay --- ------------------------ ---------------------- ---------------------- ----- 1 ios 0001.0203.0400 [Down] FDB 0000-0001.0203.0400 TenGigE0/0/0/2 2 abc 0001.0203.0401 [Ok] FDB ios Not present 3 bcd 0001.0203.0402 [Ok] Hit abc TenGigE0/0 Replies dropped: 0 If the target was a MEP, verify that the last hop shows “Hit” in the Relay field to confirm connectivity to the peer MEP. If the Relay field contains “MPDB” for any of the hops, then the target MAC address was not found in the bridge MAC learning table at that hop, and the result is relying on CCM learning. This result can occur under normal conditions, but it can also indicate a problem. If you used the ping ethernet cfm command before using the traceroute ethernet cfm command, then the MAC address should have been learned. If “MPDB” is appearing in that case, then this indicates a problem at that point in the network. |
Unidirectional Link Detection Protocol
Unidirectional Link Detection (UDLD) is a single-hop physical link protocol for monitoring an ethernet link, including both point-to-point and shared media links. This is a Cisco-proprietary protocol to detect link problems, which are not detected at the physical link layer. This protocol is specifically targeted at possible wiring errors, when using unbundled fiber links, where there can be a mismatch between the transmitting and receiving connections of a port.
- UDLD Operation
- Types of Fault Detection
- UDLD Modes of Operation
- UDLD Aging Mechanism
- State Machines
- Main FSM
- Detection FSM
UDLD Operation
UDLD works by exchanging protocol packets between the neighboring devices. In order for UDLD to work, both devices on the link must support UDLD and have it enabled on respective ports.
UDLD sends an initial PROBE message on the ports where it is configured. Once UDLD receives a PROBE message, it sends periodic ECHO (hello) messages. Both messages identify the sender and its port, and also contain some information about the operating parameters of the protocol on that port. They also contain the device and port identifiers for any neighbor devices that the local device has heard from, on the port. Similarly, each device gets to know where it is connected and where its neighbors are connected.
This information can then be used to detect faults and miswiring conditions. The protocol operates an aging mechanism by means of which information from neighbors that is not periodically refreshed is eventually timed out. This mechanism can also be used for fault detection.
A FLUSH message is used to indicate that UDLD is disabled on a port, which causes the peers to remove the local device from their neighbor cache, to prevent it from being aged out.
If a problem is detected, UDLD disables the affected interface and also notifies the user. This is to avoid further network problems beyond traffic loss, such as loops which are not detected or prevented by STP.
Types of Fault Detection
UDLD can detect these types of faults:
-
Transmit faults — These are cases where there has been a failure in transmitting packets from the local port to the peer device, but packets continue to be received from the peer. These faults are caused by failure of the physical link (where notification at layer 1 of unidirectional link faults is not supported by the media) as well as packet path faults on the local or peer device.
-
Miswiring faults — These are cases where the receiving and transmitting sides of a port on the local device are connected to different peer ports (on the same device or on different devices). This can occur when using unbundled fibers to connect fiber optic ports.
-
Loopback faults — These are cases where the receiving and transmitting sides of a port are connected to each other, creating a loopback condition. This can be an intentional mode of operation, for certain types of testing, but UDLD must not be used in these cases.
-
Receive faults — The protocol includes a heartbeat that is transmitted at a negotiated periodic interval to the peer device. Missed heartbeats can therefore be used to detect failures on the receiving side of the link (where they do not result in interface state changes). These could be caused by a unidirectional link with a failure only affecting the receiving side, or by a link which has developed a bidirectional fault. This detection depends on reliable, regular packet transmission by the peer device. For this reason, the UDLD protocol has two (configurable) modes of operation which determine the behavior on a heartbeat timeout. These modes are described in the section UDLD Modes of Operation.
UDLD Modes of Operation
UDLD Aging Mechanism
This is a scenario that happens in a receive fault condition. Aging of UDLD information happens when the port that runs UDLD does not receive UDLD packets from the neighbor port for duration of hold time. The hold time for the port is dictated by the remote port and depends on the message interval at the remote side. The shorter the message interval, the shorter is the hold time and the faster the detection. The hold time is three times the message interval in Cisco IOS XR Software.
UDLD information can age out due to the high error rate on the port caused by some physical issue or duplex mismatch. Such packet drop does not mean that the link is unidirectional and UDLD in normal mode does not disable such link.
It is important to choose the right message interval in order to ensure proper detection time. The message interval should be fast enough to detect the unidirectional link before the forwarding loop is created. The default message interval is 60 seconds. The detection time is equal to approximately three times the message interval. So, when using default UDLD timers, UDLD does not time out the link faster than the STP aging time.
State Machines
UDLD uses two types of finite state machines (FSMs), generally referred as state machines. The Main FSM deals with all the phases of operation of the protocol while the Detection FSM handles only the phases that determine the status of a port.
Main FSM
The Main FSM can be in one of these states:
-
Linkup: Port is up and running, and UDLD is in the process of detecting a neighbor.
-
Detection: A hello message from a new neighbor has been received and the Detection FSM is running to determine the status of the port.
-
Advertisement: The Detection FSM has run and concluded that the port is operating correctly, periodic hellos will continue to be sent and hellos from neighbors monitored.
-
Port shutdown: The Detection FSM detected a fault, or all neighbors were timed out in Aggressive mode, and the port has been disabled as a result.
Detection FSM
The Detection FSM can be in one of these states:
-
Unknown: Detection has not yet been performed or UDLD has been disabled.
-
Unidirectional detected: A unidirectional link condition has been detected because a neighbor does not see the local device, the port will be disabled.
-
Tx/Rx loop: A loopback condition has been detected by receiving a TLV with the ports own identifiers, the port will be disabled.
-
Neighbor mismatch: A miswiring condition has been detected in which a neighbor can identify other devices than those the local device can see and the port will be disabled.
-
Bidirectional detected: UDLD hello messages are exchanged successfully in both directions, the port is operating correctly.
Configuration Examples for Ethernet OAM
Configuration Examples for Ethernet CFM
- Ethernet CFM Domain Configuration: Example
- Ethernet CFM Service Configuration: Example
- Flexible Tagging for an Ethernet CFM Service Configuration: Example
- Continuity Check for an Ethernet CFM Service Configuration: Example
- MIP Creation for an Ethernet CFM Service Configuration: Example
- Cross-check for an Ethernet CFM Service Configuration: Example
- Other Ethernet CFM Service Parameter Configuration: Example
- MEP Configuration: Example
- Ethernet CFM Show Command: Examples
- AIS for CFM Configuration: Examples
- AIS for CFM Show Commands: Examples
- show ethernet cfm interfaces ais Command: Example
- show ethernet cfm local meps Command: Examples
- show ethernet cfm local meps detail Command: Example
Ethernet CFM Domain Configuration: Example
This example shows how to configure a basic domain for Ethernet CFM:
configure ethernet cfm traceroute cache hold-time 1 size 3000 domain Domain_One level 1 id string D1 commit
Ethernet CFM Service Configuration: Example
This example shows how to create a service for an Ethernet CFM domain:
service Bridge_Service bridge group BD1 bridge-domain B1 service Cross_Connect_1 xconnect group XG1 p2p X1 commit
Flexible Tagging for an Ethernet CFM Service Configuration: Example
This example shows how to set the number of tags in CFM packets from down MEPs in a CFM domain service:
configure ethernet cfm domain D1 level 1 service S2 bridge group BG1 bridge-domain BD2 tags 1 commit
Continuity Check for an Ethernet CFM Service Configuration: Example
This example shows how to configure continuity-check options for an Ethernet CFM service:
continuity-check archive hold-time 100 continuity-check loss auto-traceroute continuity-check interval 100ms loss-threshold 10 commit
MIP Creation for an Ethernet CFM Service Configuration: Example
This example shows how to enable MIP auto-creation for an Ethernet CFM service:
RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# mip auto-create all RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# commit
Cross-check for an Ethernet CFM Service Configuration: Example
This example shows how to configure cross-check for MEPs in an Ethernet CFM service:
mep crosscheck mep-id 10 mep-id 20 commit
Other Ethernet CFM Service Parameter Configuration: Example
This example shows how to configure other Ethernet CFM service options:
maximum-meps 4000 log continuity-check errors commit exit exit exit
MEP Configuration: Example
This example shows how to configure a MEP for Ethernet CFM on an interface:
interface TenGigE 0/0/0/1 ethernet cfm mep domain Dm1 service Sv1 mep-id 1 commit
Ethernet CFM Show Command: Examples
These examples show how to verify the configuration of Ethernet Connectivity Fault Management (CFM):
Example 1
This example shows how to display all the maintenance points that have been created on an interface:
RP/0/RP0/CPU0:router# show ethernet cfm local maintenance-points Domain/Level Service Interface Type ID MAC -------------------- ------------------- ----------------- ------ ---- -------- fig/5 bay Gi0/10/0/12 Dn MEP 2 44:55:66 fig/5 bay Gi0/0/1/0 MIP 55:66:77 fred/3 barney Gi0/1/0/0 Dn MEP 5 66:77:88!
Example 2
This example shows how to display all the CFM configuration errors on all domains:
RP/0/RP0/CPU0:router# show ethernet cfm configuration-errors Domain fig (level 5), Service bay * MIP creation configured using bridge-domain blort, but bridge-domain blort does not exist. * An Up MEP is configured for this domain on interface TenGigE0/0/0/3 and an Up MEP is also configured for domain blort, which is at the same level (5). * A MEP is configured on interface TenGigE0/0/0/1 for this domain/service, which has CC interval 100ms, but the lowest interval supported on that interface is 1s
Example 3
This example shows how to display operational state for local maintenance end points (MEPs):
RP/0/RP0/CPU0:router# show ethernet cfm local meps A - AIS received I - Wrong interval R - Remote Defect received V - Wrong Level L - Loop (our MAC received) T - Timed out (archived) C - Config (our ID received) M - Missing (cross-check) X - Cross-connect (wrong MAID) U - Unexpected (cross-check) P - Peer port down Domain foo (level 6), Service bar ID Interface (State) Dir MEPs/Err RD Defects AIS ----- ------------------------ --- -------- -- ------- --- 100 Gi1/1/0/1 (Up) Up 0/0 N A L7 Domain fred (level 5), Service barney ID Interface (State) Dir MEPs/Err RD Defects AIS ----- ------------------------ --- -------- -- ------- --- 2 Gi0/1/0/0 (Up) Up 3/2 Y RPC L6 Domain foo (level 6), Service bar ID Interface (State) Dir MEPs/Err RD Defects AIS ----- ------------------------ --- -------- -- ------- --- 100 Gi1/1/0/1 (Up) Up 0/0 N A Domain fred (level 5), Service barney ID Interface (State) Dir MEPs/Err RD Defects AIS ----- ------------------------ --- -------- -- ------- --- 2 Gi0/1/0/0 (Up) Up 3/2 Y RPC
Example 4
This example shows how to display operational state of other maintenance end points (MEPs) detected by a local MEP:
RP/0/RP0/CPU0:router# show ethernet cfm peer meps Flags: > - Ok I - Wrong interval R - Remote Defect received V - Wrong level L - Loop (our MAC received) T - Timed out C - Config (our ID received) M - Missing (cross-check) X - Cross-connect (wrong MAID) U - Unexpected (cross-check) Domain fred (level 7), Service barney Down MEP on TenGigE0/0/0/1, MEP-ID 2 ================================================================================ St ID MAC address Port Up/Downtime CcmRcvd SeqErr RDI Error -- ----- -------------- ------- ----------- --------- ------ ----- ----- > 1 0011.2233.4455 Up 00:00:01 1234 0 0 0 R> 4 4455.6677.8899 Up 1d 03:04 3456 0 234 0 L 2 1122.3344.5566 Up 3w 1d 6h 3254 0 0 3254 C 2 7788.9900.1122 Test 00:13 2345 6 20 2345 X 3 2233.4455.6677 Up 00:23 30 0 0 30 I 3 3344.5566.7788 Down 00:34 12345 0 300 1234 V 3 8899.0011.2233 Blocked 00:35 45 0 0 45 T 5 5566.7788.9900 00:56 20 0 0 0 M 6 0 0 0 0 U> 7 6677.8899.0011 Up 00:02 456 0 0 0 Domain fred (level 7), Service fig Down MEP on TenGigE0/0/0/12, MEP-ID 3 ================================================================================ St ID MAC address Port Up/Downtime CcmRcvd SeqErr RDI Error -- ----- -------------- ------- ----------- -------- ------ ----- ----- > 1 9900.1122.3344 Up 03:45 4321 0 0 0
Example 5
This example shows how to display operational state of other maintenance end points (MEPs) detected by a local MEP with details:
RP/0/RP0/CPU0:router# show ethernet cfm peer meps detail Domain dom3 (level 5), Service ser3 Down MEP on TenGigE0/0/0/1 MEP-ID 1 ================================================================================ Peer MEP-ID 10, MAC 0001.0203.0403 CFM state: Wrong level, for 00:01:34 Port state: Up CCM defects detected: V - Wrong Level CCMs received: 5 Out-of-sequence: 0 Remote Defect received: 5 Wrong Level: 0 Cross-connect (wrong MAID): 0 Wrong Interval: 5 Loop (our MAC received): 0 Config (our ID received): 0 Last CCM received 00:00:06 ago: Level: 4, Version: 0, Interval: 1min Sequence number: 5, MEP-ID: 10 MAID: String: dom3, String: ser3 Port status: Up, Interface status: Up Domain dom4 (level 2), Service ser4 Down MEP on TenGigE0/0/0/2 MEP-ID 1 ================================================================================ Peer MEP-ID 20, MAC 0001.0203.0402 CFM state: Ok, for 00:00:04 Port state: Up CCMs received: 7 Out-of-sequence: 1 Remote Defect received: 0 Wrong Level: 0 Cross-connect (wrong MAID): 0 Wrong Interval: 0 Loop (our MAC received): 0 Config (our ID received): 0 Last CCM received 00:00:04 ago: Level: 2, Version: 0, Interval: 10s Sequence number: 1, MEP-ID: 20 MAID: String: dom4, String: ser4 Chassis ID: Local: ios; Management address: 'Not specified' Port status: Up, Interface status: Up Peer MEP-ID 21, MAC 0001.0203.0403 CFM state: Ok, for 00:00:05 Port state: Up CCMs received: 6 Out-of-sequence: 0 Remote Defect received: 0 Wrong Level: 0 Cross-connect (wrong MAID): 0 Wrong Interval: 0 Loop (our MAC received): 0 Config (our ID received): 0 Last CCM received 00:00:05 ago: Level: 2, Version: 0, Interval: 10s Sequence number: 1, MEP-ID: 21 MAID: String: dom4, String: ser4 Port status: Up, Interface status: Up Peer MEP-ID 601, MAC 0001.0203.0402 CFM state: Timed Out (Standby), for 00:15:14, RDI received Port state: Down CCM defects detected: Defects below ignored on local standby MEP I - Wrong Interval R - Remote Defect received T - Timed Out P - Peer port down CCMs received: 2 Out-of-sequence: 0 Remote Defect received: 2 Wrong Level: 0 Wrong Interval: 2 Loop (our MAC received): 0 Config (our ID received): 0 Last CCM received 00:15:49 ago: Level: 2, Version: 0, Interval: 10s Sequence number: 1, MEP-ID: 600 MAID: DNS-like: dom5, String: ser5 Chassis ID: Local: ios; Management address: 'Not specified' Port status: Up, Interface status: Down
AIS for CFM Configuration: Examples
Example 1
This example shows how to configure Alarm Indication Signal (AIS) transmission for a CFM domain service:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# ethernet cfm RP/0/RP0/CPU0:router(config-cfm)# domain D1 level 1 RP/0/RP0/CPU0:router(config-cfm-dmn)# service S1 bridge group BG1 bridge-domain BD2 RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# ais transmission interval 1m cos 7 RP/0/RP0/CPU0:routerconfigure RP/0/RP0/CPU0:router(config)# ethernet cfm RP/0/RP0/CPU0:router(config-cfm)# domain D1 level 1 RP/0/RP0/CPU0:router(config-cfm-dmn)# service Cross_Connect_1 xconnect group XG1 p2p RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# ais transmission interval 1m cos 7
Example 2
This example shows how to configure AIS logging for a Connectivity Fault Management (CFM) domain service to indicate when AIS or LCK packets are received:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# ethernet cfm RP/0/RP0/CPU0:router(config-cfm)# domain D1 level 1 RP/0/RP0/CPU0:router(config-cfm-dmn)# service S2 bridge group BG1 bridge-domain BD2 RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# log ais RP/0/RP0/CPU0:routerconfigure RP/0/RP0/CPU0:router(config)# ethernet cfm RP/0/RP0/CPU0:router(config-cfm)# domain D1 level 1 RP/0/RP0/CPU0:router(config-cfm-dmn)# service Cross_Connect_1 xconnect group XG1 p2p RP/0/RP0/CPU0:router(config-cfm-dmn-svc)# log ais
This example shows how to configure AIS transmission on a CFM interface.
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface TenGigE 0/1/0/2 RP/0/RP0/CPU0:router(config-if)# ethernet cfm RP/0/RP0/CPU0:router(config-if-cfm)# ais transmission up interval 1m cos 7
AIS for CFM Show Commands: Examples
show ethernet cfm interfaces ais Command: Example
This example shows how to display the information published in the Interface AIS table:
RP/0/RP0/CPU0:router# show ethernet cfm interfaces ais Defects (from at least one peer MEP): A - AIS received I - Wrong interval R - Remote Defect received V - Wrong Level L - Loop (our MAC received) T - Timed out (archived) C - Config (our ID received) M - Missing (cross-check) X - Cross-connect (wrong MAID) U - Unexpected (cross-check) P - Peer port down D - Local port down Trigger Transmission AIS --------- Via --------------------------- Interface (State) Dir L Defects Levels L Int Last started Packets ------------------------ --- - ------- ------- - --- ------------ -------- TenGigE0/0/0/0 (Up) Dn 5 RPC 6 7 1s 01:32:56 ago 5576 TenGigE0/0/0/0 (Up) Up 0 M 2,3 5 1s 00:16:23 ago 983 TenGigE0/0/0/1 (Dn) Up D 7 60s 01:02:44 ago 3764 TenGigE0/0/0/2 (Up) Dn 0 RX 1!
show ethernet cfm local meps Command: Examples
Example 1: Default
This example shows how to display statistics for local maintenance end points (MEPs):
RP/0/RP0/CPU0:router# show ethernet cfm local meps A - AIS received I - Wrong interval R - Remote Defect received V - Wrong Level L - Loop (our MAC received) T - Timed out (archived) C - Config (our ID received) M - Missing (cross-check) X - Cross-connect (wrong MAID) U - Unexpected (cross-check) P - Peer port down Domain foo (level 6), Service bar ID Interface (State) Dir MEPs/Err RD Defects AIS ----- ------------------------ --- -------- -- ------- --- 100 Gi1/1/0/1 (Up) Up 0/0 N A 7 Domain fred (level 5), Service barney ID Interface (State) Dir MEPs/Err RD Defects AIS ----- ------------------------ --- -------- -- ------- --- 2 Gi0/1/0/0 (Up) Up 3/2 Y RPC 6
Example 2: Domain Service
This example shows how to display statistics for MEPs in a domain service:
RP/0/RP0/CPU0:router# show ethernet cfm local meps domain foo service bar detail Domain foo (level 6), Service bar Down MEP on TenGigE0/0/0/1, MEP-ID 100 ================================================================================ Interface state: Up MAC address: 1122.3344.5566 Peer MEPs: 0 up, 0 with errors, 0 timed out (archived) CCM generation enabled: No AIS generation enabled: Yes (level: 7, interval: 1s) Sending AIS: Yes (started 01:32:56 ago) Receiving AIS: Yes (from lower MEP, started 01:32:56 ago) Domain fred (level 5), Service barney Down MEP on TenGigE0/0/0/1, MEP-ID 2 ================================================================================ Interface state: Up MAC address: 1122.3344.5566 Peer MEPs: 3 up, 2 with errors, 0 timed out (archived) Cross-check defects: 0 missing, 0 unexpected CCM generation enabled: Yes (Remote Defect detected: Yes) CCM defects detected: R - Remote Defect received P - Peer port down C - Config (our ID received) AIS generation enabled: Yes (level: 6, interval: 1s) Sending AIS: Yes (to higher MEP, started 01:32:56 ago) Receiving AIS: No
Example 4: Detail
This example shows how to display detailed statistics for MEPs in a domain service:
RP/0/RP0/CPU0:router# show ethernet cfm local meps detail Domain foo (level 6), Service bar Down MEP on TenGigE0/0/0/1, MEP-ID 100 ================================================================================ Interface state: Up MAC address: 1122.3344.5566 Peer MEPs: 0 up, 0 with errors, 0 timed out (archived) CCM generation enabled: No AIS generation enabled: Yes (level: 7, interval: 1s) Sending AIS: Yes (started 01:32:56 ago) Receiving AIS: Yes (from lower MEP, started 01:32:56 ago) Domain fred (level 5), Service barney Down MEP on TenGigE0/0/0/1, MEP-ID 2 ================================================================================ Interface state: Up MAC address: 1122.3344.5566 Peer MEPs: 3 up, 2 with errors, 0 timed out (archived) Cross-check defects: 0 missing, 0 unexpected CCM generation enabled: Yes (Remote Defect detected: Yes) CCM defects detected: R - Remote Defect received P - Peer port down C - Config (our ID received) AIS generation enabled: Yes (level: 6, interval: 1s) Sending AIS: Yes (to higher MEP, started 01:32:56 ago) Receiving AIS: No
show ethernet cfm local meps detail Command: Example
Use the show ethernet cfm local meps detail command to display MEP-related EFD status information. This example shows that EFD is triggered for MEP-ID 100:
RP/0/RP0/CPU0:router# show ethernet cfm local meps detail Domain foo (level 6), Service bar Down MEP on TenGigE0/0/0/1, MEP-ID 100 ================================================================================ Interface state: Up MAC address: 1122.3344.5566 Peer MEPs: 0 up, 0 with errors, 0 timed out (archived) Cross-check errors: 2 missing, 0 unexpected CCM generation enabled: No AIS generation enabled: Yes (level: 7, interval: 1s) Sending AIS: Yes (started 01:32:56 ago) Receiving AIS: Yes (from lower MEP, started 01:32:56 ago) EFD triggered: Yes Domain fred (level 5), Service barney Down MEP on TenGigE0/0/0/1, MEP-ID 2 ================================================================================ Interface state: Up MAC address: 1122.3344.5566 Peer MEPs: 3 up, 0 with errors, 0 timed out (archived) Cross-check errors: 0 missing, 0 unexpected CCM generation enabled: Yes (Remote Defect detected: No) AIS generation enabled: Yes (level: 6, interval: 1s) Sending AIS: No Receiving AIS: No EFD triggered: No
Note | You can also verify that EFD has been triggered on an interface using the show interfaces and show interfaces brief commands. When an EFD trigger has occurred, these commands will show the interface status as up and the line protocol state as down. |
Feedback