Verifying and Isolating Fault

This article describes the initiation of loop back and link trace messages to verify and isolate a fault.

CLI Configurations

At Switch1

• Initiate Traceroute to isolate any link failure (error/fault/defect).

your product# traceroute ethernet mac 00:05:02:03:04:02 domain OP7 vlan 2
Traceroute to Macaddress 00:05:02:03:04:02    in domain  OP7 at level 7
with vlanId 2
------------------------------------------------------
Hops  Host  Ingress MAC   Ingress Action  Relay Action
Next Host   Egress MAC    Egress Action    Fwd Status
------------------------------------------------------
1   00:02:02:03:04:01:00:02  00:02:02:03:04:02   IngOK  RlyFDB
    00:06:02:03:04:01:00:02          -           EgrOK  Forwarded
2   00:06:02:03:04:01:00:02  00:00:00:00:00:00          RlyFDB
    -                                            EgrOK  Forwarded 

Shows there is a link failure between Switch1 and Switch5, as no reply is received with Relay Action as RlyHit.

• Initiate the LoopBack Transaction to verify any link failure (error/fault/defect)

your product# ping  ethernet mac 00:06:02:03:04:02 domain OP7 vlan 2
Sending 1 Ethernet CFM loopback messages, timeout is 5 seconds
Success rate is 100.0 percent 1/1

Shows there is no link failure between Switch1 and Switch6.

• Initiate the LoopBack Transaction to verify any link failure (error/fault/defect)

your product# ping ethernet mac 00:05:02:03:04:02 domain OP7 vlan 2
Sending 1 Ethernet CFM loopback messages, timeout is 5 seconds
Success rate is 0.000 percent 0/1

Shows there is a link failure between Switch6 and Switch5.

SNMP Configurations

At Switch1

• Initiate traceroute to isolate any link failure (error/fault/defect). [Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 1]

% snmp0 set {{fsMIEcfmMepTransmitLtmTargetIsMepId.0.1.1.1 false}}
% snmp0 set {{fsMIEcfmMepTransmitLtmTargetMacAddress.0.1.1.1 00:05:02:03:04:02}}
% snmp0 set {{fsMIEcfmMepTransmitLtmStatus.0.1.1.1 transmit}}

• Walk the Ltrcache Table.

% snmp0 walk x fsMIY1731LtrTable { puts $x }
{1.3.6.1.4.1.29601.2.7.1.2.6.1.3.0.1.1.1.1.1 INTEGER 41}
{1.3.6.1.4.1.29601.2.7.1.2.6.1.3.0.1.1.1.1.2 INTEGER 52}

Shows there is a link failure between Switch1 and Switch5, as data of only the first two hops is present in the Ltrcache.

• Initiate the loopback transaction to MEP on Switch6 for verifying any link failure (error/fault/defect)
  [Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 1]

% snmp0 set {{fsMIEcfmMepTransmitLbmMessages.0.1.1.1 1}}
% snmp0 set {{fsMIEcfmMepTransmitLbmDestMacAddress.0.1.1.1  00:06:02:03:04:02}}
% snmp0 set {{fsMIEcfmMepTransmitLbmDestIsMepId.0.1.1.1 false}}
% snmp0 set {{fsMIEcfmMepTransmitLbmStatus.0.1.1.1 transmit}}

• Verify transmission of loopback messages between Switch1 and Switch6.[Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 1]

% snmp0 get {fsMIEcfmMepLbrIn.0.1.1.1}
{1.3.6.1.4.1.2076.160.1.0.7.1.20.0.1.1.1 Unsigned32 1}
% snmp0 get {fsMIEcfmMepTransmitLbmMessages.0.1.1.1}
{1.3.6.1.4.1.2076.160.1.0.7.1.30.0.1.1.1 INTEGER 0}

Shows there is no link failure between Switch1 and Switch6.

• Initiate the loopback transaction to MEP on Switch5 for verifying any link failure (error/fault/defect). [Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 1]

% snmp0 set {{fsMIEcfmMepTransmitLbmMessages.0.1.1.1 1}}
% snmp0 set {{fsMIEcfmMepTransmitLbmDestMacAddress.0.1.1.1 00:05:02:03:04:02}}
% snmp0 set {{fsMIEcfmMepTransmitLbmDestIsMepId.0.1.1.1 false}}
% snmp0 set {{fsMIEcfmMepTransmitLbmStatus.0.1.1.1 transmit}}

• Verify transmission of loopback messages between Switch1 and Switch5.[Index: ContextID = 0, MD-Index = 1, MA-Index = 1, MEP-ID = 1]

% snmp0 get {fsMIEcfmMepLbrIn.0.1.1.1}
{1.3.6.1.4.1.2076.160.1.0.7.1.20.0.1.1.1 Unsigned32 1}
% snmp0 get {fsMIEcfmMepTransmitLbmMessages.0.1.1.1}
{1.3.6.1.4.1.2076.160.1.0.7.1.30.0.1.1.1 INTEGER 0}

Shows there is link failure between Switch 1 and Switch 5.