How to get SNMP data using pysnmp?

Question

I want to get snmp data by using python pysnmp module. I was using command line to get SNMP data but now I want to read it using pysnmp module.

SNMP command -

snmpwalk -v 1 -c public <ip address>:<port> xyz::pqr

I was using command like above. Now I tried something like below -

import netsnmp

def getmac():
    oid = netsnmp.VarList(netsnmp.Varbind('.1.3.6.1.2.1.17.7.1.2.2.1.2'))
    res = netsnmp.snmpgetbulk(oid, Version = 1, DestHost='ip',
                           Community='pub')
    return res

print getmac()

I'm facing error - import netsnmp. No module netsnmp

Anyone can give me suggestion how I can get snmp data from the snmp server with python?

Answer 1

You seem to be using the netsnmp module as opposed to the pysnmp.

If you want to use pysnmp, then this example may help:

from pysnmp.hlapi import *

for (errorIndication,
     errorStatus,
     errorIndex,
     varBinds) in nextCmd(SnmpEngine(),
                          CommunityData('public', mpModel=0),
                          UdpTransportTarget(('demo.snmplabs.com', 161)),
                          ContextData(),
                          ObjectType(ObjectIdentity('1.3.6.1.2.1.17.7.1.2.2.1.2'))):
    if errorIndication or errorStatus:
        print(errorIndication or errorStatus)
        break
    else:
        for varBind in varBinds:
            print(' = '.join([x.prettyPrint() for x in varBind]))

UPDATE:

The above loop will fetch one OID-value per iteration. If you want to fetch data more efficiently, one option is to stuff more OIDs into the query (in form of many ObjectType(...) parameters).

Or you can switch onto the GETBULK PDU type which can be done by changing your nextCmd call into bulkCmd like this.

from pysnmp.hlapi import *

for (errorIndication,
     errorStatus,
     errorIndex,
     varBinds) in bulkCmd(SnmpEngine(),
        CommunityData('public'),
        UdpTransportTarget(('demo.snmplabs.com', 161)),
        ContextData(),
        0, 25,  # fetch up to 25 OIDs one-shot
        ObjectType(ObjectIdentity('1.3.6.1.2.1.17.7.1.2.2.1.2'))):
    if errorIndication or errorStatus:
        print(errorIndication or errorStatus)
        break
    else:
        for varBind in varBinds:
            print(' = '.join([x.prettyPrint() for x in varBind]))

Keep in mind that GETBULK command support was first introduced in SNMP v2c, that is you can't use it over SNMP v1.