Trigger a Loopback Test

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. This can be used to check the ability of the network to forward different sized frames.

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.

Procedure

In the navigation pane, expand Configuration > Serviceability > Diagnostics.
Click CFM.
Click the LBM tab.
Configure the loopback test properties as required.
Click Apply.
To trigger the loopback test, double-click in the Status field, select transmit.
Click Apply.
To update the loopback test, click the Refresh button.

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 Note: Exception: smltVirtual is not supported on 5320 Series.	Specifies the source mode of the transmit loopback service: nodal smltVirtual — Use the smltVirtual option with B-VLANs only. The default is nodal.