"""
Fetch whole SNMP table
++++++++++++++++++++++

Send a series of SNMP GETNEXT requests using the following options:

* with SNMPv1, community 'public'
* over IPv4/UDP
* to an Agent at demo.snmplabs.com:161
* for some columns of the IF-MIB::ifEntry table
* with MIB lookup enabled
* stop when response OIDs leave the scopes of initial OIDs

Functionally similar to:

| $ snmpwalk -v1 -c public demo.snmplabs.com IF-MIB::ifDescr IF-MIB::ifType IF-MIB::ifMtu IF-MIB::ifSpeed IF-MIB::ifPhysAddress IF-MIB::ifType

"""#
from pysnmp.hlapi.v1arch import *

iterator = nextCmd(
    SnmpDispatcher(),
    CommunityData('public', mpModel=0),
    UdpTransportTarget(('demo.snmplabs.com', 161)),
    ObjectType(ObjectIdentity('IF-MIB', 'ifDescr')),
    ObjectType(ObjectIdentity('IF-MIB', 'ifType')),
    ObjectType(ObjectIdentity('IF-MIB', 'ifMtu')),
    ObjectType(ObjectIdentity('IF-MIB', 'ifSpeed')),
    ObjectType(ObjectIdentity('IF-MIB', 'ifPhysAddress')),
    ObjectType(ObjectIdentity('IF-MIB', 'ifType')),
    lookupMib=True,
    lexicographicMode=False
)

for errorIndication, errorStatus, errorIndex, varBinds in iterator:

    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]))
