Usage Scenario
The mep mep-id command can be used to create MEPs that define a connectivity fault management (CFM) area. CFM supports continuity check (CC), loopback (LB), and link trace (LT) functions on end-to-end (E2E) links between MEPs.
MEPs are classified into the following types:
- Inward-facing MEP: sends packets to other interfaces on the same device.
- Outward-facing MEP: sends packets out of the interface on which the MEP is configured.
Prerequisites
An MD and an MA have been configured using the cfm md and ma commands, respectively.
The MA has been bound to a virtual leased line (VLL) or virtual private LAN service (VPLS) using the
map command.
A QinQ VLAN tag termination sub-interface has been configured using the qinq termination pe-vid command in the case of QinQ VLAN tag termination sub-interface access.
Follow-up Procedure
Run the mep ccm-send enable command to enable the MEP in the MA to send continuity check messages (CCMs).
Precautions
Specifications of MEPs to be created in an MA are as follows:
- VLAN-based and interface-based MEPs are mutually exclusive. Common inward-based and outward-facing MEPs are mutually exclusive.
- A single outward-facing interface-based MEP can be created. Multiple inward-facing interface-based MEPs can be created on a device. An interface supports only one inward-facing interface-based MEP.
- Only one VLAN-based MEP can be created.
The maximum number of MEPs that can be created varies according to interface board types and router models. For details about specifications, see the specification description of a specific interface board or router.
Precautions for creating a MEP in an MA are as follows:
- An MA in which an inward-facing interface-based MEP is to be created must have been associated with a service (for example, a VLAN, L2VC, or VSI), and the service must have been configured on the interface on which the MEP is to be created.
- An MA does not need to be associated with a service if an outward-facing interface-based MEP is to be created in the MA. If the MA has been associated with a service, the service must be configured on the interface on which the MEP is to be created.
- The MA must be associated with a VLAN if a VLAN-based MEP is to be created in the MA.
- An MA in which a PW-based MEP is to be created must have been associated with a service (for example, a VSI), and the specified PW must belong to the service.