SnmpMgrGetTrap function (mgmtapi.h)

Article
10/13/2021

[SNMP is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Instead, use Windows Remote Management, which is the Microsoft implementation of WS-Man.]

The SnmpMgrGetTrap function returns outstanding trap data that the caller has not received if trap reception is enabled. This function is an element of the SNMP Management API.

In addition to the information returned by this function, the SnmpMgrGetTrapEx function returns the address of the transport source and the community string of the trap.

Syntax

BOOL SNMP_FUNC_TYPE SnmpMgrGetTrap(
  [out] AsnObjectIdentifier *enterprise,
  [out] AsnNetworkAddress   *IPAddress,
  [out] AsnInteger          *genericTrap,
  [out] AsnInteger          *specificTrap,
  [out] AsnTimeticks        *timeStamp,
  [out] RFC1157VarBindList  *variableBindings
);

Parameters

[out] enterprise

Pointer to an AsnObjectIdentifier structure to receive the enterprise that generated the SNMP trap.

[out] IPAddress

Pointer to a variable to receive the address of the agent that generated the SNMP trap.

[out] genericTrap

Pointer to a variable to receive an indicator of the generic trap. This parameter can be one of the following values.

Value	Meaning
SNMP_GENERICTRAP_COLDSTART	The agent is initializing protocol entities on the managed mode. It may alter objects in its view.
SNMP_GENERICTRAP_WARMSTART	The agent is reinitializing itself but it will not alter objects in its view.
SNMP_GENERICTRAP_LINKDOWN	An attached interface has changed from the "up" state to the "down" state. The first variable in the variable bindings list identifies the interface.
SNMP_GENERICTRAP_LINKUP	An attached interface has changed from the "down" state to the "up" state. The first variable in the variable bindings list identifies the interface.
SNMP_GENERICTRAP_AUTHFAILURE	An SNMP entity has sent an SNMP message, but it has falsely claimed to belong to a known community.
SNMP_GENERICTRAP_EGPNEIGHLOSS	An EGP peer has changed to the "down" state. The first variable in the variable bindings list identifies the IP address of the EGP peer.
SNMP_GENERICTRAP_ENTERSPECIFIC	An extraordinary event has occurred and it is identified in the specificTrap parameter with an enterprise-specific value.

[out] specificTrap

Pointer to a variable to receive an indication of the specific trap generated.

[out] timeStamp

Pointer to a variable to receive the time stamp.

[out] variableBindings

Pointer to an SnmpVarBindList structure to receive the variable bindings list.

Return value

If the function returns a trap, the return value is TRUE. The code for the error can be retrieved by calling SnmpGetLastError immediately after the call.

You should call the SnmpMgrGetTrap function repeatedly until it returns FALSE (zero). The function may also return the following error codes.

Return code	Description
SNMP_MGMTAPI_TRAP_ERRORS	Indicates errors were encountered; traps are not accessible.
SNMP_MGMTAPI_NOTRAPS	Indicates no traps are available.
SNMP_MEM_ALLOC_ERROR	Indicates a memory allocation error.

Remarks

The application must always call the SnmpMgrTrapListen function before calling the SnmpMgrGetTrap function. This is because the event handle pointed to by the phTrapAvailable parameter of the SnmpMgrTrapListen function enables the event-driven acquisition of SNMP traps. The SNMP Management API signals an application's event when the SNMP Trap Service delivers a trap.

The application can also poll the SnmpMgrGetTrap function for traps at regular intervals. In this case, the application should repeatedly call SnmpMgrGetTrap until the function returns zero.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	mgmtapi.h
Library	Mgmtapi.lib
DLL	Mgmtapi.dll