(Optional) Setting the EFM Working Mode on an Interface

Context

EFM supports two connection modes: active and passive. Table 1 describes capabilities for processing OAMPDUs supported by these modes.

**Table 1** Capabilities for processing OAMPDUs in active and passive modes
Action	Active Mode	Passive Mode
Initiate a connection request by sending an Information OAMPDU during the discovery process	Supported	Not supported
Respond to a connection request during the discovery process	Supported	Supported
Send Information OAMPDUs	Supported	Supported
Send Event Notification OAMPDUs	Supported	Supported
Send Loopback Control OAMPDUs	Supported	Not supported
Respond to Loopback Control OAMPDUs	Supported (The remote EFM entity must work in active mode.)	Supported

EFM can be configured on Layer 2 and Layer 3 Ethernet interfaces. By default, an Ethernet interface works in Layer 2 mode. Before configuring EFM on a Layer 3 Ethernet interface, switch the Ethernet interface to Layer 3 mode.

Procedure

Run system-view
The system view is displayed.
Run interface interface-type interface-number
The view of the interface at one end of the link is displayed.
(Optional) On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.

By default, an Ethernet interface works in Layer 2 mode.

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
Run efm mode { active | passive }
The EFM working mode on the interface is configured.

By default, EFM on an interface works in active mode.
- The EFM working mode can be set on an interface only after EFM is enabled globally and before EFM is enabled on the interface. The EFM working mode on an interface cannot be changed after EFM is enabled on the interface.
- When using EFM to monitor a link, ensure that either of the interfaces at both ends of the link operates in active mode.
  If both ends of a link are configured to work in active EFM mode, link detection can be implemented.
  
  If both ends of a link are configured to work in passive mode, link detection cannot be implemented.