GET command

pysnmp.hlapi.v1arch.asyncore.getCmd(snmpDispatcher, authData, transportTarget, *varBinds, **options)

Initiate SNMP GET query over SNMPv1/v2c.

Based on passed parameters, prepares SNMP GET packet (RFC 1905#section-4.2.1) and schedules its transmission by I/O framework at a later point of time.

Parameters:
  • snmpDispatcher (SnmpDispatcher) – Class instance representing asyncore-based asynchronous event loop and associated state information.
  • authData (CommunityData) – Class instance representing SNMPv1/v2c credentials.
  • transportTarget (UdpTransportTarget or) – Udp6TransportTarget Class instance representing transport type along with SNMP peer address.
  • *varBinds (tuple of OID-value pairs or ObjectType) – One or more class instances representing MIB variables to place into SNMP request.
Other Parameters:
 

**options – Request options:

  • lookupMib - load MIB and resolve response MIB variables at the cost of slightly reduced performance. Default is False.
  • cbFun (callable) - user-supplied callable that is invoked to pass SNMP response data or error to user at a later point of time. Default is None.
  • cbCtx (object) - user-supplied object passing additional parameters to/from cbFun. Default is None.

Note

The SnmpDispatcher object may be expensive to create, therefore it is advised to maintain it for the lifecycle of the application/thread for as long as possible.

Note

User-supplied cbFun callable must have the following call signature:

  • snmpDispatcher: SnmpDispatcher Class instance representing asyncore-based asynchronous event loop and associated state information.
  • stateHandle (int): Unique request identifier. Can be used for matching multiple ongoing requests with received responses.
  • errorIndication (str): evaluates to True to indicate SNMP dispatcher error.
  • errorStatus (int): evaluates to True to indicate SNMP PDU error.
  • errorIndex (int): Non-zero value refers to varBinds[errorIndex-1]
  • varBinds (tuple): A sequence of ObjectType class instances representing MIB variables returned in SNMP response in exactly the same order as varBinds in request.
  • cbCtx (object): Original user-supplied object.
Returns:stateHandle (int) – Unique request identifier. Can be used for matching received responses with ongoing requests.
Raises:PySnmpError – Or its derivative indicating that an error occurred while performing SNMP operation.

Examples

>>> from pysnmp.hlapi.v1arch.asyncore import *
>>>
>>> def cbFun(snmpDispatcher, stateHandle, errorIndication,
>>>           errorStatus, errorIndex, varBinds, cbCtx):
>>>     print(errorIndication, errorStatus, errorIndex, varBinds)
>>>
>>> snmpDispatcher = SnmpDispatcher()
>>>
>>> stateHandle = getCmd(
>>>     snmpDispatcher,
>>>     CommunityData('public'),
>>>     UdpTransportTarget(('demo.snmplabs.com', 161)),
>>>     ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr', 0)),
>>>     cbFun=cbFun
>>> )
>>>
>>> snmpDispatcher.transportDispatcher.runDispatcher()