Various SNMP versions
*********************


Multiple SNMP USM users
=======================

Listen and respond to SNMP GET/SET/GETNEXT/GETBULK queries with the
following options:

* SNMPv3

* with USM user:

     * 'usr-md5-des', auth: MD5, priv DES or

     * 'usr-sha-none', auth: SHA, no privacy

     * 'usr-sha-aes128', auth: SHA, priv AES

* allow access to SNMPv2-MIB objects (1.3.6.1.2.1)

* over IPv4/UDP, listening at 127.0.0.1:161

* using asyncio network transport (available since Python 3.4)

Either of the following Net-SNMP commands will walk this Agent:

   $ snmpwalk -v3 -u usr-md5-des -l authPriv -A authkey1 -X privkey1 localhost .1.3.6
   $ snmpwalk -v3 -u usr-sha-none -l authNoPriv -a SHA -A authkey1 localhost .1.3.6
   $ snmpwalk -v3 -u usr-sha-aes128 -l authPriv -a SHA -A authkey1 -x AES -X privkey1 localhost .1.3.6

Requires Python 3.4 and later!

   from pysnmp.entity import engine, config
   from pysnmp.entity.rfc3413 import cmdrsp, context
   from pysnmp.carrier.asyncio.dgram import udp
   import asyncio

   # Get the event loop for this thread
   loop = asyncio.get_event_loop()

   # Create SNMP engine with autogenernated engineID and pre-bound
   # to socket transport dispatcher
   snmpEngine = engine.SnmpEngine()

   # Transport setup

   # UDP over IPv4
   config.addTransport(
       snmpEngine,
       udp.domainName,
       udp.UdpTransport().openServerMode(('127.0.0.1', 161))
   )

   # SNMPv3/USM setup

   # user: usr-md5-des, auth: MD5, priv DES
   config.addV3User(
       snmpEngine, 'usr-md5-des',
       config.usmHMACMD5AuthProtocol, 'authkey1',
       config.usmDESPrivProtocol, 'privkey1'
   )
   # user: usr-sha-none, auth: SHA, priv NONE
   config.addV3User(
       snmpEngine, 'usr-sha-none',
       config.usmHMACSHAAuthProtocol, 'authkey1'
   )
   # user: usr-sha-none, auth: SHA, priv AES
   config.addV3User(
       snmpEngine, 'usr-sha-aes128',
       config.usmHMACSHAAuthProtocol, 'authkey1',
       config.usmAesCfb128Protocol, 'privkey1'
   )

   # Allow full MIB access for each user at VACM
   config.addVacmUser(snmpEngine, 3, 'usr-md5-des', 'authPriv', (1, 3, 6, 1, 2, 1), (1, 3, 6, 1, 2, 1))
   config.addVacmUser(snmpEngine, 3, 'usr-sha-none', 'authNoPriv', (1, 3, 6, 1, 2, 1), (1, 3, 6, 1, 2, 1))
   config.addVacmUser(snmpEngine, 3, 'usr-sha-aes128', 'authPriv', (1, 3, 6, 1, 2, 1), (1, 3, 6, 1, 2, 1))

   # Get default SNMP context this SNMP engine serves
   snmpContext = context.SnmpContext(snmpEngine)

   # Register SNMP Applications at the SNMP engine for particular SNMP context
   cmdrsp.GetCommandResponder(snmpEngine, snmpContext)
   cmdrsp.SetCommandResponder(snmpEngine, snmpContext)
   cmdrsp.NextCommandResponder(snmpEngine, snmpContext)
   cmdrsp.BulkCommandResponder(snmpEngine, snmpContext)

   # Run asyncio main loop
   loop.run_forever()

"Download" script.

See also: library reference.
