SnmpStartup

The SnmpStartup function notifies the Microsoft WinSNMP implementation that the WinSNMP application requires the implementation's services. The WinSNMP SnmpStartup function enables the implementation to initialize and to return to the application the version of the Windows SNMP Application Programming Interface (WinSNMP API), the level of SNMP communications that the implementation supports, and the implementation's default translation and retransmission modes.

Note  A WinSNMP application must call the SnmpStartup function successfully before it calls any other WinSNMP function.

SNMPAPI_STATUS SnmpStartup(
  smiLPUINT32 nMajorVersion,   // major version number of the WinSNMP API
  smiLPUINT32 nMinorVersion,   // minor version number of the WinSNMP API
  smiLPUINT32 nLevel,          // level of SNMP the implementation supports
  smiLPUINT32 nTranslateMode,  // default entity/context translation mode
  smiLPUINT32 nRetransmitMode  // default retransmission mode 
);

Parameters

nMajorVersion

[out] Pointer to an unsigned long integer variable to receive the major version number of the WinSNMP API that the implementation supports. For example, to indicate that the implementation supports WinSNMP version 2.0, the function returns a value of 2.

nMinorVersion

[out] Pointer to an unsigned long integer variable to receive the minor version number of the WinSNMP API that the implementation supports. For example, to indicate that the implementation supports WinSNMP version 2.0, the function returns a value of 0.

nLevel

[out] Pointer to an unsigned long integer variable to receive the highest level of SNMP communications the implementation supports. Upon successful return, this parameter contains a value of 2. For a description of level 2 support, see Levels of SNMP Support.

nTranslateMode

[out] Pointer to an unsigned long integer variable to receive the default translation mode in effect for the implementation. The translation mode applies to the implementation's interpretation of the entity parameter that the WinSNMP application passes to the SnmpStrToEntity function. The translation mode also applies to the string parameter that the WinSNMP application passes to the SnmpStrToContext function. This parameter can be one of the following values.

Value	Meaning
SNMPAPI_TRANSLATED	The implementation uses its database to translate user-friendly names for SNMP entities and managed objects. The implementation translates them into their SNMPv1 or SNMPv2C components.
SNMPAPI_UNTRANSLATED_V1	The implementation interprets SNMP entity parameters as SNMP transport addresses, and context parameters as SNMP community strings. For SNMPv2 destination entities, the implementation creates outgoing SNMP messages that contain a value of zero in the version field.
SNMPAPI_UNTRANSLATED_V2	The implementation interprets SNMP entity parameters as SNMP transport addresses, and context parameters as SNMP community strings. For SNMPv2 destination entities, the implementation creates outgoing SNMP messages that contain a value of 1 in the version field.

For additional information, see Setting the Entity and Context Translation Mode.

nRetransmitMode

[out] Pointer to an unsigned long integer variable to receive the default retransmission mode in effect for the implementation. This parameter can be one of the following values.

Value	Meaning
SNMPAPI_OFF	The implementation is not executing the retransmission policy of the WinSNMP application.
SNMPAPI_ON	The implementation is executing the retransmission policy of the WinSNMP application.

For additional information, see About Retransmission.

Return Values

If the function succeeds, the return value is SNMPAPI_SUCCESS, and the parameters contain appropriate values, as indicated in the preceding parameter descriptions.

If the function fails, the return value is SNMPAPI_FAILURE. To get extended error information, call SnmpGetLastError specifying a NULL value in its session parameter. The SnmpGetLastError function can return one of the following errors. For additional information, see the Remarks section that follows.

Remarks

A WinSNMP application must call the SnmpStartup function successfully at least once, before it calls any other WinSNMP function. If a WinSNMP application does call another WinSNMP function, before it successfully calls SnmpStartup, the implementation returns the error SNMPAPI_NOT_INITIALIZED.

The WinSNMP application can call SnmpGetLastError for error information, or retry SnmpStartup if a call to the SnmpStartup function fails. When SnmpStartup returns SNMPAPI_FAILURE, and a subsequent call to SnmpGetLastError returns SNMP_ALLOC_ERROR, the WinSNMP application can elect to wait. It can retry the call to SnmpStartup when the implementation has adequate free resources.

A WinSNMP application can call SnmpStartup multiple times. For example, it may need to retry the function call for the reasons discussed preceding. A WinSNMP application must also call SnmpCleanup at least once, as the last WinSNMP function call before it terminates. Multiple SnmpStartup calls do not require multiple SnmpCleanup calls.

For additional information, see Levels of SNMP Support and About SNMP Versions.

Requirements

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Unsupported.
  Header: Declared in Winsnmp.h.
  Library: Use Wsnmp32.lib.

See Also

WinSNMP API Overview, WinSNMP Functions, SnmpStrToEntity, SnmpStrToContext, SnmpCleanup