Verifying and Isolating Fault

This article describes the verification and isolation of a fault using loopback and link trace messages.

CLI Configurations

At CUST1

• Initiate the Loopback transaction from CUST1 to MEP at CUST3 to verify the link failure, where CUST3 MEP’s MAC Address is the learned remote MAC Address known from the command show ethernet cfm service
  your product# ping ethernet mac 00:03:02:03:04:02 domain OP1 vlan 2

Sending 1 Ethernet CFM loopback messages, timeout is 5 seconds
Success rate is 0.000 percent 0/1

your product#

• Initiate Traceroute to MEP at bridge CUST3 to isolate link failure (error/fault/defect).
  your product# traceroute ethernet mac 00:03:02:03:04:02 domain OP1 vlan 2

Traceroute to Macaddress 00:03:02:03:04:02    in domain  OP1 at level 5
with vlanId 2
------------------------------------------------------
Hops    Host  Ingress MAC Ingress Action  Relay Action
Next Host     Egress MAC  Egress Action    Fwd Status
------------------------------------------------------
1   00:01:02:03:04:01:00:02  00:02:02:03:04:02   IngOK  RlyFDB
    00:02:02:03:04:01:00:02  00:02:02:03:04:03   EgrOK  Forwarded

Shows there is a link failure between CUST1 and CUST3, as no reply is received from CUST3 and with the Relay Action as RlyHit

• Initiate the Loopback transaction to MIP at CUST2 to verify if there is a link failure.
  your product# ping ethernet mac 00:02:02:03:04:02 domain OP1 vlan 2

Sending 1 Ethernet CFM loopback messages, timeout is 5 seconds
Success rate is 100.0 percent 1/1

Shows no link failure between CUST1 and CUST2

SNMP Configurations

At CUST1

• Initiate the loopback transaction from CUST1 to MEP at CUST3 to verify the link failure, where CUST3 MEP’s MAC address is the learned remote MAC. [Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 10]
  % snmp0 set {{fsMIEcfmMepTransmitLbmMessages.0.1.1.10 5 }}
  % snmp0 set {{fsMIEcfmMepTransmitLbmDestMacAddress.0.1.1.10 00:03:02:03:04:02 }}
  % snmp0 set {{fsMIEcfmMepTransmitLbmDestIsMepId.0.1.1.10 false }}
  % snmp0 set {{fsMIEcfmMepTransmitLbmStatus.0.1.1.10 transmit }}

• Check whether the LBRs are not received.
  % snmp0 get {fsMIEcfmMepLbrIn.0.1.1.10 }

{1.3.6.1.4.1.2076.160.1.0.7.1.20.0.1.1.10 Unsigned32 0}

• Initiate traceroute to MEP at bridge CUST1 for isolating link failure (error/fault/defect). [Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 10]
  % snmp0 set {{fsMIEcfmMepTransmitLtmTargetIsMepId.0.1.1.10 false }}
  % snmp0 set {{fsMIEcfmMepTransmitLtmTargetMacAddress.0.1.1.10 00:03:02:03:04:02 }}
  % snmp0 set {{fsMIEcfmMepTransmitLtmStatus.0.1.1.10 transmit }}

• Check whether LTM is transmitted successfully
  % snmp0 walk x fsMIEcfmLtrTable { puts $x }

{1.3.6.1.4.1.2076.160.1.0.8.1.3.0.1.1.10.2.1 Unsigned32 63}
{1.3.6.1.4.1.2076.160.1.0.8.1.4.0.1.1.10.2.1 INTEGER true}
{1.3.6.1.4.1.2076.160.1.0.8.1.5.0.1.1.10.2.1 INTEGER false}
{1.3.6.1.4.1.2076.160.1.0.8.1.6.0.1.1.10.2.1 {OCTET STRING} 00:01:02:03:04:01:00:02}
{1.3.6.1.4.1.2076.160.1.0.8.1.7.0.1.1.10.2.1 {OCTET STRING} 00:02:02:03:04:01:00:02}
{1.3.6.1.4.1.2076.160.1.0.8.1.8.0.1.1.10.2.1 INTEGER rlyFdb}
{1.3.6.1.4.1.2076.160.1.0.8.1.9.0.1.1.10.2.1 INTEGER 0}
{1.3.6.1.4.1.2076.160.1.0.8.1.10.0.1.1.10.2.1 {OCTET STRING} {}}
{1.3.6.1.4.1.2076.160.1.0.8.1.11.0.1.1.10.2.1 {OBJECT IDENTIFIER} 0}
{1.3.6.1.4.1.2076.160.1.0.8.1.12.0.1.1.10.2.1 {OCTET STRING} {}}
{1.3.6.1.4.1.2076.160.1.0.8.1.13.0.1.1.10.2.1 INTEGER ingOk}
{1.3.6.1.4.1.2076.160.1.0.8.1.14.0.1.1.10.2.1 {OCTET STRING} 00:02:02:03:04:02}
{1.3.6.1.4.1.2076.160.1.0.8.1.15.0.1.1.10.2.1 INTEGER 1}
{1.3.6.1.4.1.2076.160.1.0.8.1.16.0.1.1.10.2.1 {OCTET STRING} 53:6C:6F:74:30:2F:32}
{1.3.6.1.4.1.2076.160.1.0.8.1.17.0.1.1.10.2.1 INTEGER egrOK}
{1.3.6.1.4.1.2076.160.1.0.8.1.18.0.1.1.10.2.1 {OCTET STRING} 00:02:02:03:04:03}
{1.3.6.1.4.1.2076.160.1.0.8.1.19.0.1.1.10.2.1 INTEGER 1}
{1.3.6.1.4.1.2076.160.1.0.8.1.20.0.1.1.10.2.1 {OCTET STRING} 53:6C:6F:74:30:2F:33}
{1.3.6.1.4.1.2076.160.1.0.8.1.21.0.1.1.10.2.1 {OCTET STRING} 1F:00:04:00:02}

• Initiate the loopback transaction to MIP at CUST2 for verifying if there is a link failure. [Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 10]
  % snmp0 set {{fsMIEcfmMepTransmitLbmMessages.0.1.1.10 5 }}
  % snmp0 set {{fsMIEcfmMepTransmitLbmDestMacAddress.0.1.1.10 00:02:02:03:04:02 }}
  % snmp0 set {{fsMIEcfmMepTransmitLbmDestIsMepId.0.1.1.10 false }}
  % snmp0 set {{fsMIEcfmMepTransmitLbmStatus.0.1.1.10 transmit }}

• Check whether LBMs are transmitted successfully and LBRs are received
  % snmp0 get {fsMIEcfmMepLbrIn.0.1.1.10 }

{1.3.6.1.4.1.2076.160.1.0.7.1.20.0.1.1.10 Unsigned32 5}

Shows no link failure between CUST1 and CUST2.