# Table operations

## Fetch scalar and table variables

Send a series of SNMP GETBULK requests with the following options:

- with SNMPv3 with user ‘usr-md5-des’, MD5 auth and DES privacy protocols

- over IPv4/UDP

- to an Agent at 104.236.166.95:161

- with values non-repeaters = 1, max-repetitions = 25

- for two OIDs in tuple form (first OID is non-repeating)

- stop on end-of-mib condition for both OIDs

This script performs similar to the following Net-SNMP command:

$ snmpbulkwalk -v3 -l authPriv -u usr-md5-des -A authkey1 -X privkey1 -C n1 -C r25 -ObentU 104.236.166.95 1.3.6.1.2.1.1 1.3.6.1.4.1.1

    from pysnmp.entity import engine, config
    from pysnmp.entity.rfc3413 import cmdgen
    from pysnmp.carrier.asyncore.dgram import udp

    # Create SNMP engine instance
    snmpEngine = engine.SnmpEngine()

    #
    # SNMPv3/USM setup
    #

    # user: usr-md5-des, auth: MD5, priv DES
    config.addV3User(
        snmpEngine, 'usr-md5-des',
        config.usmHMACMD5AuthProtocol, 'authkey1',
        config.usmDESPrivProtocol, 'privkey1'
    )
    config.addTargetParams(snmpEngine, 'my-creds', 'usr-md5-des', 'authPriv')

    #
    # Setup transport endpoint and bind it with security settings yielding
    # a target name
    #

    # UDP/IPv4
    config.addTransport(
        snmpEngine,
        udp.domainName,
        udp.UdpSocketTransport().openClientMode()
    )
    config.addTargetAddr(
        snmpEngine, 'my-router',
        udp.domainName, ('104.236.166.95', 161),
        'my-creds'
    )

    # Error/response receiver
    # noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
    def cbFun(snmpEngine, sendRequesthandle, errorIndication,
              errorStatus, errorIndex, varBindTable, cbCtx):
        if errorIndication:
            print(errorIndication)
            return  # stop on error
        if errorStatus:
            print('%s at %s' % (errorStatus.prettyPrint(),
                                errorIndex and varBindTable[-1][int(errorIndex) - 1][0] or '?'))
            return  # stop on error
        for varBindRow in varBindTable:
            for oid, val in varBindRow:
                print('%s = %s' % (oid.prettyPrint(), val.prettyPrint()))
        return True  # signal dispatcher to continue walking

    # Prepare initial request to be sent
    cmdgen.BulkCommandGenerator().sendVarBinds(
        snmpEngine,
        'my-router',
        None, '',  # contextEngineId, contextName
        0, 25,  # non-repeaters, max-repetitions
        (((1, 3, 6, 1, 2, 1, 1), None),
         ((1, 3, 6, 1, 4, 1, 1), None)),
        cbFun
    )

    # Run I/O dispatcher which would send pending queries and process responses
    snmpEngine.transportDispatcher.runDispatcher()

`Download` script.

## Pull MIB subtree

Send a series of SNMP GETNEXT requests * with SNMPv3 with user ‘usr-none-none’, no auth and no privacy protocols * over IPv4/UDP * to an Agent at 104.236.166.95:161 * for an OID in string form * stop whenever received OID goes out of initial prefix (it may be a table)

This script performs similar to the following Net-SNMP command:

$ snmpwalk -v3 -l noAuthNoPriv -u usr-none-none -ObentU 104.236.166.95:161 1.3.6.1.2.1.1

    from pysnmp.entity import engine, config
    from pysnmp.carrier.asyncore.dgram import udp
    from pysnmp.entity.rfc3413 import cmdgen
    from pysnmp.proto import rfc1902

    # Initial OID prefix
    initialOID = rfc1902.ObjectName('1.3.6.1.2.1.1')

    # Create SNMP engine instance
    snmpEngine = engine.SnmpEngine()

    #
    # SNMPv3/USM setup
    #

    # user: usr-none-none, auth: none, priv: none
    config.addV3User(
        snmpEngine, 'usr-none-none',
    )
    config.addTargetParams(snmpEngine, 'my-creds', 'usr-none-none', 'noAuthNoPriv')

    #
    # Setup transport endpoint and bind it with security settings yielding
    # a target name
    #

    # UDP/IPv4
    config.addTransport(
        snmpEngine,
        udp.domainName,
        udp.UdpSocketTransport().openClientMode()
    )
    config.addTargetAddr(
        snmpEngine, 'my-router',
        udp.domainName, ('104.236.166.95', 161),
        'my-creds'
    )

    # Error/response receiver
    # noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
    def cbFun(snmpEngine, sendRequestHandle, errorIndication,
              errorStatus, errorIndex, varBindTable, cbCtx):
        if errorIndication:
            print(errorIndication)
            return
        if errorStatus:
            print('%s at %s' % (errorStatus.prettyPrint(),
                                errorIndex and varBindTable[-1][int(errorIndex) - 1][0] or '?'))
            return  # stop on error
        for varBindRow in varBindTable:
            for oid, val in varBindRow:
                if initialOID.isPrefixOf(oid):
                    print('%s = %s' % (oid.prettyPrint(), val.prettyPrint()))
                else:
                    return False  # signal dispatcher to stop
        return True  # signal dispatcher to continue

    # Prepare initial request to be sent
    cmdgen.NextCommandGenerator().sendVarBinds(
        snmpEngine,
        'my-router',
        None, '',  # contextEngineId, contextName
        [(initialOID, None)],
        cbFun
    )

    # Run I/O dispatcher which would send pending queries and process responses
    snmpEngine.transportDispatcher.runDispatcher()

`Download` script.

See also: library reference.