Trigger a Loopback Test

Before you begin

On the source and destination nodes, you must configure a CFM MD, MA, and MEP.
Enable the MEP.
Assign a nodal MEP to the B-VLAN.

About this task

Use this procedure to trigger a loopback test.

The LBM packet is often compared to ping. An MEP transmits the loopback message to an intermediate or endpoint within a domain for the purpose of fault verification. Use this function to check the ability of the network to forward different sized frames.

Procedure

In the navigation pane, expand Configuration > Serviceability > Diagnostics.
Select CFM.
Select the LBM tab.
Configure the loopback test properties as required.
Select Apply.
In Status, select transmit.
Select Apply.
Select Refresh.

LBM Field Descriptions

Use the data in the following table to use the LBM tab.


Name	Description
DomainIndex	Specifies the MD index value.
AssociationIndex	Specifies the MA index value.
Index	Specifies the Maintenance Endpoint index value.
DomainName	Specifies the MD name.
AssociationName	Specifies the MA name.
DestMacAddress	Specifies the remote MAC address to reach the MEP/MIP.
Messages	Specifies the number of loopback messages to be transmitted. The default is 1.
VlanPriority	Specifies the priority. The default is 7.
SeqNumber	Specifies the transaction identifier/sequence number of the first loopback message (to be) sent. The default is 0.
ResultOk	Indicates the result of the operation: true: The Loopback Messages will be (or have been) sent. false: The Loopback Messages will not be sent. The default is true.
Status	Indicates the status of the transmit loopback service: ready: The service is available. transmit: The service is transmitting, or about to transmit, the Loopback messages. abort: The service is aborted or about to abort the Loopback messages. The default is ready.
Result	Displays the LBM result.
TimeoutInt	Specifies the timeout interval in seconds. The default value is 3 seconds.
InterFrameInt	Specifies the interval between LBM frames with a range of (0..1000) msecs and a default value of 500 msecs. The value of 0 msecs indicates to send the frames as fast as possible. The default is 500.
TestPattern	Specifies the testfill pattern: allZero — null signal without cyclic redundancy check allZeroCrc — null signal with cyclic redundancy check with 32-bit polynomial pseudoRandomBitSequence — pseudo-random-bit-sequence without cyclic redundancy check pseudoRandomBitSequenceCrc — pseudo-random-bit-sequence with cyclic redundancy check with 32-bit polynomial. A cyclic redundancy check is a code that detects errors. The default value is allZero.
DataSize	Specifies the data type-length-value (TLV) size. The default is 0.
FrameSize	Specifies the frame-size. The default is 0.
Sourcemode	Specifies the source mode of the transmit loopback service: nodal noVlanMac — Use this value with C-VLAN only. When you select this option, even if a VLAN MAC address exists, the system uses the CFM C-MAC as the BMAC-SA. smltVirtual — Use the smltVirtual option with B-VLANs only. The default is nodal.