Not all event variables contain values in the Communication Link Down event in Spectrum

Products

• Spectrum
• Network Observability

Issue/Introduction

Not all event variables contain values in the Communication Link Down event in Spectrum

Environment

Release : Any

Component : Spectrum Core / Events / Alarms

Resolution

The "standard" link down trap by the mib definition in the IF-MIB only contains 3 variables: ifIndex, ifAdminStatus, ifOperStatus. The following is from the IF-MIB:

-- definition of interface-related traps.

linkDown NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkDown trap signifies that the SNMP entity, acting in
an agent role, has detected that the ifOperStatus object for
one of its communication links is about to enter the down
state from some other state (but not from the notPresent
state). This other state is indicated by the included value
of ifOperStatus."
::= { snmpTraps 3 }


However, different vendors like to "add" their own custom variables like ifName, sysName and ifAlias to name a few. So, the AlertMap file in the $SPECROOT/SS/CsVendor/IETF/AlertMap file has been configured with known variables some vendors add to their link down traps.


{d "%w- %d %m-, %Y - %T"} A(n) {t} device, named {m}, has detected a Communication Link Down. ifIndex = {I 1}, ifAdminStatus = {T ifAdminStatus 5}, ifOperStatus = {T ifOperStatus 6}, ifDescr = {S 3}, ifType = {S 4}.

Additional Variables:
sysObjectID = {o 7}
sysName = {S 8}
locIfReason = {S 9}
ifReasonForStatusCes = {T ContIFReasForStat 10}
ifPhysLocationCes = {T ContIFPhysLoc 11}
ifPhysRelPosCes = {I 12}
ifIpAddrCes = {O 13}
ifNameCes = {S 14}
ifTunnelRemoteIpAddrCes = {O 15}
ifName = {S 16}
ifAlias = {S 17}
usdSnmpTrapTrapSeverity = {T UsdTrapTrapSeverity 18}

(event [{e}])


If you do not see a variable populated (like ifAlias) then that means that variable was not a varbind sent with the link down trap from that device.