Does TRAP and Inform Receiver supported in PYSNMP for SNMP v3?

Question

I can see for Trap reciver for SNMP v1 and V2 from its docs site.

It does not support SNMP v3 trap.

Is there something for v3 trap receiver in PYSNMP?

And also is there something for inform receiver ?

Answer 1

Yes, here is a SNMPv3 notification receiver example. The same code works for INFORMs as well. In fact, the same code supports SNMPv1 and v2c TRAPs/INFORMs.

UPDATED:

SNMPv1/v2c TRAP receiver is obliged to check SNMP community name in the incoming message (a very light security measure). That's why you need to configure SNMP community name to SNMP engine on the receiving end.

If you need more details on SNMP engine operations (like peer's network address), there is a collection of callbacks placed at strategic locations inside pysnmp which you can listen to to gather the information about currently running request. Here's an example. The getTransportInfo call can also be used, but it's considered obsolete by now.

You can experiment with it by sending INFORMs to demo.pysnmp.com (port 162).

Answer 2

I get the following error when executing: '#python3 EXAMPLE-above.py'

'#udp.domainName, AttributeError: module 'pysnmp.carrier.asyncore.dgram.udp' has no attribute 'domainName' '

Centos 7

Python 3.6.8

pysnmp 5.0.0

pysmi-0.3.4

pyasn1-0.4.8

net-snmp5.8.1-pre

'#python3 -v -c 'import pysnmp' 2>&1 | grep pysmi --> produce nothing'

'#python -v -c 'import pysnmp' 2>&1 | grep pysmi'

'#zipimport: found 100 names in /usr/lib/python2.7/site-packages/pysmi-0.3.4-py2.7.egg'

'#python3 -v -c 'import pysnmp' 2>&1 | grep pyasn1'

'# zipimport: found 77 names in '/usr/local/lib/python3.6/site-packages/pyasn1-0.4.8-py3.6.egg'

FIXED: git clone all the dependancie source, unzip the packages, cd package-source-dir then: #python3 setup.py install

As this is my first python/snmp project there is most probably better/cleanr ways to resolve. Would appreciate to know the correct way.

Happy hacking :)

Answer 3

Thanks, @llya Etingof 's solution in GitHub.

example:

"""
Multiple SNMP USM users
+++++++++++++++++++++++

Receive SNMP TRAP/INFORM messages with the following options:

* SNMPv1/SNMPv2c
  * with SNMP community "public"
  * over IPv4/UDP, listening at 127.0.0.1:162

* SNMPv3
* with USM users:

  * 'usr-md5-des', auth: MD5, priv DES, ContextEngineId: 8000000001020304
  * 'usr-md5-none', auth: MD5, priv NONE, ContextEngineId: 8000000001020304
  * 'usr-sha-aes128', auth: SHA, priv AES, ContextEngineId: 8000000001020304

* over IPv4/UDP, listening at 127.0.0.1:162
* print received data on stdout

Either of the following Net-SNMP commands will send notifications to this
receiver:

| $ snmptrap -v2c -c public 127.0.0.1:162 123 1.3.6.1.6.3.1.1.5.1 1.3.6.1.2.1.1.5.0 s test

| $ snmptrap -v3 -u usr-md5-des -l authPriv -A authkey1 -X privkey1 -e 8000000001020304 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1
| $ snmptrap -v3 -u usr-md5-none -l authNoPriv -A authkey1 -e 8000000001020304 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1
| $ snmpinform -v3 -u usr-sha-aes128 -l authPriv -a SHA -A authkey1 -x AES -X privkey1 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1

"""#
from pysnmp.entity import engine, config
from pysnmp.carrier.asyncore.dgram import udp
from pysnmp.entity.rfc3413 import ntfrcv
from pysnmp.proto.api import v2c

# 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', 162))
)

# SNMPv1/2c setup
config.addV1System(snmpEngine, 'my-area', 'public')

# 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-md5-des, auth: MD5, priv DES, securityEngineId: 8000000001020304
# this USM entry is used for TRAP receiving purposes
config.addV3User(
    snmpEngine, 'usr-md5-des',
    config.usmHMACMD5AuthProtocol, 'authkey1',
    config.usmDESPrivProtocol, 'privkey1',
    securityEngineId=v2c.OctetString(hexValue='8000000001020304')
)

# user: usr-md5-none, auth: MD5, priv NONE
config.addV3User(
    snmpEngine, 'usr-md5-none',
    config.usmHMACMD5AuthProtocol, 'authkey1'
)

# user: usr-md5-none, auth: MD5, priv NONE, securityEngineId: 8000000001020304
# this USM entry is used for TRAP receiving purposes
config.addV3User(
    snmpEngine, 'usr-md5-none',
    config.usmHMACMD5AuthProtocol, 'authkey1',
    securityEngineId=v2c.OctetString(hexValue='8000000001020304')
)

# user: usr-sha-aes128, auth: SHA, priv AES
config.addV3User(
    snmpEngine, 'usr-sha-aes128',
    config.usmHMACSHAAuthProtocol, 'authkey1',
    config.usmAesCfb128Protocol, 'privkey1'
)
# user: usr-sha-aes128, auth: SHA, priv AES, securityEngineId: 8000000001020304
# this USM entry is used for TRAP receiving purposes
config.addV3User(
    snmpEngine, 'usr-sha-aes128',
    config.usmHMACSHAAuthProtocol, 'authkey1',
    config.usmAesCfb128Protocol, 'privkey1',
    securityEngineId=v2c.OctetString(hexValue='8000000001020304')
)


# Callback function for receiving notifications
# noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
def cbFun(snmpEngine, stateReference, contextEngineId, contextName,
          varBinds, cbCtx):
    print('Notification from ContextEngineId "%s", ContextName "%s"' % (
        contextEngineId.prettyPrint(), contextName.prettyPrint()))
    for name, val in varBinds:
        print('%s = %s' % (name.prettyPrint(), val.prettyPrint()))


# Register SNMP Application at the SNMP engine
ntfrcv.NotificationReceiver(snmpEngine, cbFun)

snmpEngine.transportDispatcher.jobStarted(1)  # this job would never finish

# Run I/O dispatcher which would receive queries and send confirmations
try:
    snmpEngine.transportDispatcher.runDispatcher()
except:
    snmpEngine.transportDispatcher.closeDispatcher()
    raise

command:

| $ snmptrap -v2c -c public 127.0.0.1:162 123 1.3.6.1.6.3.1.1.5.1 1.3.6.1.2.1.1.5.0 s test

| $ snmptrap -v3 -u usr-md5-des -l authPriv -A authkey1 -X privkey1 -e 8000000001020304 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1
| $ snmptrap -v3 -u usr-md5-none -l authNoPriv -A authkey1 -e 8000000001020304 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1
| $ snmpinform -v3 -u usr-sha-aes128 -l authPriv -a SHA -A authkey1 -x AES -X privkey1 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1

stdout:

Notification from ContextEngineId "0x80004fb80543794f53335afe60", ContextName ""
1.3.6.1.2.1.1.3.0 = 123
1.3.6.1.6.3.1.1.4.1.0 = 1.3.6.1.6.3.1.1.5.1
1.3.6.1.2.1.1.5.0 = test

Notification from ContextEngineId "0x80001f88809f7b5c26ef1e1c5e00000000", ContextName ""
1.3.6.1.2.1.1.3.0 = 123
1.3.6.1.6.3.1.1.4.1.0 = 1.3.6.1.6.3.1.1.5.1

Notification from ContextEngineId "0x80001f88809f7b5c26ef1e1c5e00000000", ContextName ""
1.3.6.1.2.1.1.3.0 = 123
1.3.6.1.6.3.1.1.4.1.0 = 1.3.6.1.6.3.1.1.5.1

Notification from ContextEngineId "0x80001f88809f7b5c26ef1e1c5e00000000", ContextName ""
1.3.6.1.2.1.1.3.0 = 123
1.3.6.1.6.3.1.1.4.1.0 = 1.3.6.1.6.3.1.1.5.1