Dealing with the "OID not increasing" error
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17. I'm walking a particular Agent with the *nextCmd()* or *bulkCmd()*
    functions. It works for some OIDs, but invariably fails at certain
    OID with the *OID not increasing* error. What does it mean and how
    do I fix that?

1. The Agent you are talking to seems to be broken. The *OID not
   increasing* message means that in the course of fetching OIDs from
   the Agent, Manager receives an OID that is not greater than those
   passed in request. Due to the nature of GETNEXT/GETBULK algorithm,
   passing the same or lesser OID to Manager would result in fetching
   the same set of OIDs over and over again effectively creating an
   infinite loop between Manager and Agent so they may never reach the
   end of MIB. To prevent this the Manager tries to intervene and
   prevent such loop from happening.

   If you have to work with a broken Agent and can terminate the
   GETNEXT/GETBULK command at some point, you can pass the
   *ignoreNonIncreasingOid=True* keyword parameter to the *nextCmd()*
   or *bulkCmd()* to disable OID verification at the Manager side.

   for (errorIndication,
        errorStatus,
        errorIndex,
        varBinds) in nextCmd(SnmpEngine(),
                             CommunityData('public'),
                             UdpTransportTarget(('demo.snmplabs.com', 161)),
                             ContextData(),
                             ObjectType(ObjectIdentity('1.3.6')),
                             ignoreNonIncreasingOid=True):

       if errorIndication:
           print(errorIndication)
           break
       elif errorStatus:
           print('%s at %s' % (errorStatus.prettyPrint(),
                               errorIndex and varBinds[int(errorIndex) - 1][0] or '?'))
           break
       else:
           for varBind in varBinds:
               print(' = '.join([x.prettyPrint() for x in varBind])
