Revision 6.2.4, released on Jul 20, 2024#

  • Deleted more obsolete items.

Revision 6.2.3, released on Jul 17, 2024#

  • Removed unused dependencies.

Revision 6.2.2, released on Jul 16, 2024#

  • Removed package postfix. A helper release to enable migration.

Revision 6.2.1, released on Jul 14, 2024#

  • Cleaned up sync API leftover.

Revision 6.2.0, released on Jul 12, 2024#

  • Retired temporary sync API.

Revision 6.1.3, released on July 16, 2024#

  • Removed package postfix. A helper release to enable migration.

Revision 6.1.2, released on Mar 25, 2024#

  • Merged changes from 4.4.13.

Revision 6.1.1, released on Mar 23, 2024#

  • Fixed more access descriptors.

Revision 6.1.0, released on Mar 23, 2024#

  • Initial work to support pysmi-lextudio 1.3.0 and above.

Revision 6.0.13, released on July 16, 2024#

  • Removed package postfix. A helper release to enable migration.

Revision 6.0.12, released on Mar 23, 2024#

  • Restricted pysmi-lextudio version to 1.2.0 to avoid breaking changes.

Revision 6.0.11, released on Mar 14, 2024#

  • Fixed walkCmd bug.

Revision 6.0.10, released on Mar 13, 2024#

  • Fixed bulkWalkCmd bug.

Revision 6.0.9, released on Mar 08, 2024#

  • Added sync oneliner back.

Revision 6.0.8, released on Mar 07, 2024#

  • Fix annotations.

Revision 6.0.7, released on Mar 07, 2024#

  • Added walkCmd() and bulkWalkCmd() to hlapi.

Revision 6.0.6, released on Mar 04, 2024#

  • Improved Slim class to support IPv6.

  • Added some sync API based on asyncio.

Revision 6.0.5, released on Mar 01, 2024#

  • Added custom socket support in openServerMode.

  • Fixed various bugs in RFC3414 error handling.

Revision 6.0.4, released on Feb 28, 2024#

  • Reverted some changes in 6.0.2 on asyncio dispatch.

Revision 6.0.3, released on Feb 26, 2024#

  • Deleted asyncore related bits.

Revision 6.0.2, released on Feb 13, 2024#

  • Simplified asyncio dispatch.

  • Added ignoreNonIncreasingOid option to nextCmd and bulkCmd.

Revision 6.0.1, released on Feb 10, 2024#

  • Fixed a dispatch bug related to “Slim.close”.

Revision 6.0.0, released on Feb 10, 2024#

  • Improved asyncio “runDispatcher” method to support timeout.

  • Changed internal defaults to asyncio.

  • Converted asyncore samples to asyncio.

Revision 5.1.0, released on July 16, 2024#

  • Removed package postfix. A helper release to enable migration.

Revision 5.0.34, released on Feb 04, 2024#

  • Fixed a v3 authentication issue when wrong user name is used.

Revision 5.0.33, released on Jan 12, 2024#

  • Fixed an import error with Python 3.12.

Revision 5.0.32, released on Dec 25, 2023#

  • Added timeout and retries to Slim class.

Revision 5.0.31, released on Dec 09, 2023#

  • Added experimental Python 3.12 support based on pyasyncore. But all asyncore based API is deprecated and will be removed in the next major release.

Revision 5.0.30, released on Nov 20, 2023#

  • Added pyasn1 0.5.1 support.

Revision 5.0.29, released on Sep 12, 2023#

  • Fix asyncio hlapi double awaitable returns.

Revision 5.0.28, released on May 08, 2023#

  • Fixed SNMP engine ID generation on Windows.

Revision 5.0.27, released on Apr 28, 2023#

  • SNMPv3 crypto operations that require external dependencies made dependent on the optional external package – pysnmpcrypto.

  • By switching to pysnmpcrypto, pysnmp effectively migrates from PyCryptodomex to pyca/cryptography whenever available on the platform.

Revision 5.0.26, released on Apr 21, 2023#

  • Blocked pyasn1 new release due to its breaking changes.

Revision 5.0.25, released on Jan 26, 2023#

  • Added Slim class and simplified some examples.

Revision 5.0.24, released on Jan 22, 2023#

  • Fixed a #SNMP demo compatibility issue.

Revision 5.0.23, released on Jan 21, 2023#

  • Fixed a #SNMP demo compatibility issue.

  • Fixed passwordToKeySHA.

Revision 5.0.22, released on Jan 20, 2023#

  • Enabled Python 3.11 support.

Revision 5.0.21, released on Dec 26, 2022#

  • Switched to pyasn1/pyasn1 package.

Revision 5.0.20, released on Dec 01, 2022#

  • Removed legacy paddings in v3 packets.

Revision 5.0.18, released on Nov 13, 2022#

  • Changed web site to

  • Inherited all changes made by Splunk team.

Revision 4.4.13, released on 2019-11-XX#

  • Fixed genErr handing in Command Responder when mapping MIB instrumentation exception onto SNMP errors. Prior to this fix, genErr would never be reported back to SNMP manager.

Revision 4.4.12, released on Sep 24, 2019#

  • Fixed broken SNMPv3 msgFlag initialization on authoritative SNMP engine ID discovery. This bug causes secure communication with peer SNMP engines to stall at SNMP engine ID discovery procedure.

Revision 4.4.11, released on Aug 10, 2019#

  • Added SNMPv3 USM master and localized keys support to LCD configuration

  • Improved initial and runtime USM debugging

  • Fixed a bug in USM configuration which did not allow the same user names to be added under different security names

Revision 4.4.10, released on Jul 29, 2019#

  • Reworked VACM access control function. Most important changes include:

    • Added subtree match negation support (vacmViewTreeFamilyType)

    • Added subtree family mask support (vacmViewTreeFamilyMask)

    • Added prefix content name matching support (vacmAccessContextMatch)

    • Added key VACM tables caching for better isAccessAllowed lookup performance

    One potential incompatibility may be caused by the addContext() call which now needs to be made explicitly during low-level VACM configuration rather than be a side effect of addVacmAccess() call.

  • Rebased MIB importing code onto importlib because imp is long deprecated

  • Received MIB objects resolution made more forgiving to errors, added optional ignoreErrors parameter to ObjectType.resolveWithMib() to control that behaviour.

  • Fixed asyncore main loop to respect non-default timer resolution

  • Fixed .setTimerResolution() behaviour of abstract main loop dispatcher to update call intervals of the existing periodic dispatcher jobs

  • Fixed var-bindings initialization to prevent pyasn1 encoder failures with newer pyasn1 versions where SequenceOf type looses its default initializer.

  • Fixed crash on uninitialized component serialization left out in SNMP v1 TRAP PDU to SNMPv2/3 TRAP PDU proxy translation routine.

Revision 4.4.9, released on Feb 09, 2019#

  • Made MIB loader ignoring file and directory access errors

  • Added missing SNMP PDU error classes and their handling in Command Responder

  • Fixed crash on MIB load failure in case of directory access error

  • Fixed socket transparency option (IPV6_TRANSPARENT) to make IPv6 transparent operation functional

Revision 4.4.8, released on Dec 30, 2018#

  • Fixed Pythonized MIB load (in the source form) - made sure to turn it into a code object prior to its execution

Revision 4.4.7, released on Dec 29, 2018#

  • Copyright notice extended to the year 2019

  • Exposed ASN.1 Null type through rfc1902 module for convenience.

  • Use compile() before exec’ing MIB modules to attach filename to the stack frames (ultimately shown in traceback/debugger)

  • Fixed hlapi/v3arch transport target caching to ensure transport targets are different even if just timeout/retries options differ

  • Fixed hlapi LCD configurator to include contextName. Prior to this fix sending SNMPv3 TRAP with non-default contextName would fail.

  • Fixed possible duplicate key occurrence in the OrderedDict following a race condition

  • Fixed undefined name references in inet_pton/inet_ntop substitute routines for IPv6 in

Revision 4.4.6, released on Sep 13, 2018#

  • Improved package build and dependency tracking

  • Fixed missing LICENSE from the tarball distribution

  • Fixed CommandGeneratorLcdConfigurator.unconfigure() to fully clean up internal caches, otherwise repetitive attempts to configure the target would fail.

  • Fix to tolerate possible duplicate enumerations in Bits and Integer SMI types.

  • Fix to tolerate non-initialised entries in SNMP community table. Once a bad entry sneaked into the SNMP community table, all the subsequent SNMP v1/v2c operations failed. The fix ignores incomplete SNMP community table entries in the course of building indices.

Revision 4.4.5, released on Aug 05, 2018#

  • Added PySnmpError.cause attribute holding parent exception tuple

  • Fixed broken InetAddressType rendering caused by a pyasn1 regression

  • Fixed typo in RFC1158 module

  • Fixed possible infinite loop in GETBULK response PDU builder

  • Fixed memory leak in the config.delContext() VACM management harness

  • Fixed Bits class initialization when enumeration values are given

  • Fixed crash caused by incoming SNMPv3 message requesting SNMPv1/v2c security model

  • Fixed out-of-scope OIDs leaking at the end of SNMP table at hlapi nextCmd and bulkCmd calls when lexicographicMode = False

Revision 4.4.4, released on Jan 03, 2018#

  • Copyright notice extended to the year 2018

  • Fixed short local key expansion at 3DES key localization implementation.

Revision 4.4.3, released on Dec 22, 2017#

  • Migrated references from SourceForge

  • Added missing SHA2 support for Blumenthal key localization

  • Fixed named bits handling at rfc1902.Bits

  • Fixed missing SmiError exception class at pysnmp.proto.rfc1155

  • Fixed SNMP v1->v2c PDU proxy – error-status & error-index fields from v1 PDU get copied over to v2c PDU in addition to the exception sentinels being set

Revision 4.4.2, released on Nov 11, 2017#

  • The pysnmp version being used gets exposed to the MIB modules via the MibBuilder instance

  • The .setObjects() method of the SMI types now accepts append=False parameter to let the caller adding more than 255 elements over the course of multiple calls

  • Added support for some more missing fields of SMIv2 MACRO types

  • Example scripts rearranged in a way that IPv6 requirement is clearly encoded in the script’s name

  • Fixed SNMPv2-SMI.NotificationType to expose .set/getReference() instead of .set/getRevision() which should not be there in the first place

  • Fixed non-implied-OID encoding in SNMP table indices

  • Fixed inconsistent SNMPv3 discovery and retrying algorithm

Revision 4.4.1, released on Oct 23, 2017#

  • HMAC-SHA-2 Authentication Protocols support added (RFC-7860)

  • The pycryptodome dependency replaced with pycryptodomex as it is recommended by the upstream to avoid unwanted interference with PyCrypto package should it also be installed

  • Sphinx theme changed to Alabaster in the documentation

  • Minor adjustments towards pyasn1 0.4.x compatibility

  • Fixed ObjectIdentifier-into-ObjectIdentity casting at rfc1902.ObjectType MIB resolution harness

  • Fixed NetworkAddress object handling in SNMP table indices

  • Fixed MIB lookup by module:object.indices MIB object with InetAddressIPv{4,6} objects being in the index

  • Fixed non-translated PDU being retries at CommandGenerator what leads to wrong PDU version being sent and even a crash on incompatible PDU/SNMP message combination

Revision 4.3.10, released on Oct 06, 2017#

  • Refactored partial SNMP message decoding to make it less dependent on unpublished pyasn1 API features.

  • Fix to MibTableRow.setFromName() to keep the input parameter type when it propagates to the return value. Before this fix ObjectIdentity.prettyPrint() may crash when rendering malformed SNMP table indices.

  • Fixed NotificationReceiver to include SNMPv1 TRAP Message community string into SNMPv2c/v3 TRAP PDU

  • Fixed multiple bugs in SNMP table indices rendering, especially the InetAddressIPv6 type which was severely broken.

  • Fixed crashing Bits.prettyPrint() implementation

  • Fixed crashing Bits.clone()/subtype() implementation

  • Fixed leaking exceptions bubbling up from the asyncio and Twisted adapters

Revision 4.3.9, released on Jul 26, 2017#

  • Deprecated UsmUserData initialization parameters removed

  • Adapted to pyasn1 API changes introduced by release 0.3.1

  • Fix to a crash happening on inbound SNMP message having non-initialized fields

  • Fix to (persistent SNMP engine ID) file writing on Windows

Revision 4.3.8, released on Jun 15, 2017#

  • Security fix to the bug introduced in 4.3.6: msgAuthoritativeEngineTime stopped changing over time and was returning the same timestamp (process start time). This fix makes it growing as it should.

Revision 4.3.7, released on May 29, 2017#

  • Fixed import error in legacy NotificationOriginator implementation

Revision 4.3.6, released on May 28, 2017#

  • More instrumentation hooks added addressing security failures auditing needs.

  • SNMP table indices correlation implemented within SMI framework. The opaque InetAddress type implemented. INET-ADDRESS-MIB included into the distribution.

  • SNMP table indices resolution logic made more robust against malformed indices.

  • Fixes to lexicographicMode option documentation to make it unambiguous.

  • The ErrorIndication object is now derived from Exception so that it could be raised in exceptions.

  • The errorIndication values produced by various parts of SNMP engine unified to be ErrorIndication instances. This fixes an issue with Twisted.

  • Embedded MIB modules rebuilt with the latest pysmi adding previously missing attributes like status, description etc.

  • Fixed potential SNMP engine crash on handling incoming message at unsupported security level

Revision 4.3.5, released on Mar 24, 2017#

  • The getNext() and getBulk() calls of Twisted interface. now support ignoreNonIncreasingOid option.

  • TextualConvention is now a new-style class.

  • Fix to accidentally reset error-status when building confirmed class SNMPv1 PDU.

  • Fix to possible infinite recursion in TextualConvention.prettyIn().

  • Fixed crash when attempting to report unsupported request/notification PDU back to sender.

Revision 4.3.4, released on Mar 01, 2017#

  • Fix to low-level SNMP API example to accommodate changed pyasn1 SEQUENCE supporting iterator protocol.

  • The pyasn1 version dependency bumped (0.2.3), SEQUENCE/SEQUENCE OF API calls adjusted to accommodate changed pyasn1 API (in part of .setComponentBy*() kw flags).

  • Fixed crash on SNMP engine’s invalid message counter increment.

Revision 4.3.3, released on Feb 04, 2017#

  • Switched from now unmaintained PyCrypto to PyCryptodome.

  • Switched to new-style classes.

  • NotificationType now allows additional var-binds specified as MIB objects. A side effect of this change is that additional var-binds can only be added prior to .resolveMibObjects() is run.

  • Non-standard (but apparently used by many vendors) Reeder AES192/256 key localization algorithm implemented and set as default for usmAesCfb192Protocol and usmAesCfb256Protocol identifiers. Original and more standard implementation can still be used with the usmAesBlumenthalCfb192Protocol and usmAesBlumenthalCfb192Protocol IDs respectively.

  • TextualConvention.prettyOut() improved to produce prettier and more SMI-compliant output.

  • TextualConvention.prettyIn() implemented to handle DISPLAY-HINT based value parsing.

  • Fix to NotificationType to make additional var-binds overriding MIB objects implicitly included through NOTIFICATION-TYPE OBJECTS.

  • Fix to SNMP engine boots counter persistence on Python 3.

  • Fix to Pythonized MIBs loading when only .pyc files are present (e.g. py2exe/cx_freeze environments).

  • Fix broken 3DES key localization and encryption procedures.

  • Updated IP address for in examples.

  • Missing index added to bundled RFC1213::atEntry MIB table.

  • Twisted integration made Python3 compatible.

  • Accommodated ASN.1 SEQUENCE iteration rules change in upcoming pyasn1 version.

  • Author’s email changed, copyright extended to 2017.

Revision 4.3.2, released on Feb 12, 2016#

  • Copyright notice added to non-trivial source code files.

  • SNMP table row consistency check added. This change may break valid SNMP SET operations on tables if RowStatus column is not passed at the very end of var-binds.

  • All SNMP counters now incremented via ‘+= 1’ rather than ‘x = x + 1’ to simplify their tracking by third-party code.

  • Notification originator examples re-pointed to Notification Receiver at

  • Two more execution observer points added: rfc2576.processIncomingMsg and rfc3414.processIncomingMsg to give an insight on security modules internals.

  • TEXTUAL-CONVENTION’s DISPLAY-HINT text formatting reworked for better performance and encoding accuracy of ‘a’ and ‘t’ formats.

  • WARNING: security fix to USM - extra user entry clone removed on incoming message processing. It made USM accepting SNMPv3 TRAPs from unknown SNMP engine IDs.

  • Fix to snmpInvalidMsgs and snmpUnknownSecurityModels MIB symbols import at SNMPv3 MP model.

  • Fix to NotificationOriginator to cope with unspecified user callable.

  • Fix to OctetString.prettyOut() to pretty-print Python 3 bytes without ‘b’ qualifier.

  • Fix to better pysmi import errors handling.

  • Fix to missing next() in Python 2.5 at pysnmp.hlapi

Revision 4.3.1, released on Nov 12, 2015#

  • Added recursive resolution of ObjectIdentifier values at ObjectType by converting it to ObjectIdentity.

  • A bunch of convenience shortcuts to rfc1902.ObjectIdentity added from rfc1902.ObjectType and rfc1902.NotificationType (.addAsn1MibSource(), .addMibSource(), .loadMibs())

  • When pretty printing indices at rfc1902.ObjectType, quote only strings.

  • SNMP overview and PySNMP hlapi tutorial added to documentation.

  • Fix to __doc__ use in to make -O0 installation mode working.

  • Fix to ObjectIdentity->ObjectIdentifier attributes handover

  • Fixed crash at oneliner compatibility code on EOM response.

  • Fixed crash in hlapi.transport module.

  • Fixed OID resolution issues that roots at node 0 and 2.

  • Fix to MIB builder to fail gracefully on corrupted MIB package encounter.

  • Fix to docs distribution – now the are Sphinx-buildable out-of-the-box.

  • Source code re-linted

Revision 4.3.0, released on Sep 28, 2015#

  • Critical error fixed in key localization procedure for AES192/AES256/3DES cyphers. Previous versions might never worked properly in this respect.

  • Initial PySMI integration. Original ASN.1 MIBs could now be parsed, stored at a local pysnmp MIBs repository and loaded into SNMP Engine. Relevant example scripts added. Obsolete libsmi-based scripts removed.

  • Major rewrite of native SNMPv3 CommandGenerator and NotificationOriginator applications towards the following goals:

    • avoid binding to specific SNMP engine instance to promote single SNMP app instance using many SNMP engine instances

    • support two APIs for working with request data: one operates on the whole PDU object while the other on PDU contents

    • keep callback context data in stack rather than in stateful application cache

    • newly introduced sendVarBinds() method offers a more functional and logical signatures.

    • Promote the use of dedicated classes for dealing with OID-value pairs. Instances of those classes resemble OBJECT-IDENTITY, OBJECT-TYPE and NOTIFICATION-TYPE MIB structures.

    • Oneliner API reworked to become more generic: its LCD configuration shortcuts and and var-bindings processing code split off SNMP apps classes to stand-alone objects. The whole API also moved up in package naming hierarchy and becomes ‘pysnmp.hlapi.asyncore’ (hlapi is apparently an African fish). Old oneliner API remains fully operational at its original location.

    • Synchronous oneliner apps redesigned to offer Python generator-based API along with a more comprehensive set of accepted parameters.

    • Asyncore-based asynchronous apps reworked to become functions.

    • Twisted API moved entirely into high-level domain to be aligned with other high-level APIs. This WILL BREAK backward compatibility for those apps that use Twisted API.

    • Keep backward compatibility for all existing major/documented interfaces

  • Sphinx documentation added to source code and example scripts. Library documentation converted from .html into RsT markup.

  • Execution Observer facility implemented to give app an inside view of SNMP engine inner workings. This is thought to be a generic framework for viewing (and modifying) various internal states of pysnmp engine. Previously introduced non-standard APIs (like getting peer’s transport endpoint which is not suggested in RFCs) will be gradually migrated to this new framework.

  • Initial support for the asyncio & Trollius frameworks and coroutines-based SNMP Applications interfaces added. Both IPv4 and IPv6 datagram transports are currently supported.

  • Original asynsock transport and AsyncsockDispatcher renamed into asyncore and AsyncoreDispatcher respectively to provide better hint to fellow devs on the underlying transport being used. Backward compatibility preserved.

  • The asyncore-based transport subsystem extended to support POSIX sendmsg()/recvmsg() based socket communication what could be used, among other things, in the context of a transparent SNMP proxy application. Technically, the following features were brought into pysnmp with this update:

    • Sending SNMP packets from a non-local IP address

    • Receiving IP packets for non-local IP addresses

    • Responding to SNMP requests from exactly the same IP address the query was sent to. This proves to be useful when listening on both primary and secondary IP interfaces.

  • Internal oneliner apps configuration cache moved from respective apps objects to [a singular] snmpEngine “user context” object. That would allow for better cache reuse and allow for a single app working with many snmpEngine instances.

  • Oneliner GETBULK Command Generator now strips possible excessive OIDs off the bottom of returned var-binds table.

  • Constraints assignment shortcut added to some base rfc1902 types (Integer, Integer32, OctetString, Bits). That formally constitutes ASN.1 sub-typing.

  • Built-in debugging is now based on Python logging module.

  • Examples on a single Transport Dispatcher use with multiple SnmpEngine instances applications added.

  • Example script on transport timeout & retries manipulation added.

  • Example script explaining incoming message’s communityName re-mapping added.

  • Broadcast socket option can now be enabled with the .enableBroadcast() call for any datagram-based transport (namely, UDP and UDP6).

  • AbstractTransportDispatcher’s jobStarted() and jobFinished() methods now accept optional ‘count’ parameter which is a way for an app to indicate how many responses are expected or have been processed in bulk.

  • Example script on SNMP Agents UDP broadcast-based discovery added.

  • Oneliner transport object now supports setLocalAddress() method to force socket binding to specified local interface.

  • New public DgramSocketTransport.getLocalAddress() returns local endpoint address underlying BSD socket is currently bound to.

  • Passing request details to access control callback at CommandResponder reworked towards more robust and simple design with the execution observer facility.

  • All MIBs rebuilt with pysmi.

  • MIB instrumentation example improved to cover table index building facility.

  • Handle the case of null writer at Debug printer.

  • Do not cache snmpEngineId & snmpAdminString at CommandGenerator to let it be reused with many different snmpEngines.

  • TRAP PDU agent address evaluation at proto.api made lazy to improve startup time.

  • Multiple fixes to verify pyasn1 decoder.decode() return to withstand broken SNMP messages or its components.

  • First attempt made to make some of SNMP Engine settings persistent across reboots.

  • Make config.delTransport() returning detached transport object. Asyncio examples now use this facility to explicitly shutdown transport object.

  • Parts of SMIv1 remnant MIBs (RFC1213-MIB, RFC1158-MIB) added to provide complete compatibility with SMIv1. Symbols defined in these MIBs only present in SMIv1 so they can’t be substituted with their SMIv2 analogues.

  • MibBuilder.addMibSources() convenience method added.

  • The smi.MibBuilder() will now raise more specific exceptions (MibLoadError, MibNotFoundError) on MIB loading problems rather than more generic SmiError.

  • The oneliner’s MibVariable MIB lookup subsystem redesigned for more generality to mimic OBJECT-TYPE macro capabilities related to SNMP PDU handling. The two new classed are ObjectIdentity and ObjectType. The ObjectIdentity class additionally supports just a MIB module name initializer in which case if resolves into either first or last symbol in given MIB. Another option is just a MIB symbol initializer without specifying MIB module. This new subsystem is moved from the scope of oneliner to more common pysnmp.smi.rfc1903 scope to more naturally invoke it from whatever part of pysnmp requires MIB services.

  • MibBuilder now prepends the contents of environment variables it recognizes (PYSNMP_MIB_DIR, PYSNMP_MIB_DIRS, PYSNMP_MIB_PKGS) rather than using them instead of its default core MIBs.

  • Removed RowStatus default value as it may collide with possible subclass constraints.

  • A few additional MIB tree management methods added to MibViewController to better address ordered nature of MIB tree nodes (namely, getFirst*, getLast* family of methods).

  • Wheel distribution format now supported.

  • Fix to authoritative engine side snmpEngineID discovery procedure: respond with notInTimeWindows rather then with unsupportedSecurityLevel at time synchronization phase.

  • Fix to rfc1902.Bits type to make it accepting hex and binary initializers, cope with missing bits identifiers at prettyPrint().

  • Memory leak fixed in CommandForwarder examples.

  • Fix to BULK CommandGenerator to use the same nonRepeaters OIDs across multiple GETBULK iterations so returned table for nonRepeaters columns would hold the same var-bind.

  • Fix to CommandGenerator to make sendRequestHandle persistent across multiple iterations of GETNEXT/GETBULK queries.

  • Fix to sendNotification() error handling at NotificationOriginator.

  • Fix to preserve possible ‘fixed length’ setting atrfc1902.OctetString on clone()’ing and subtype()’ing.

  • Fix to rfc1902.OctetString & Bits to base them on OctetString class to make the ‘fixed length’ property working.

  • Fix to .clone() method of rfc1902.Bits class to make its signature matching the rest of classes. This may broke code which used to pass namedValue parameter positionally rather than binding it by name.

  • Fix to PDU translation service (proto.proxy.rfc2576) to make it initializing errorIndex & errorStatus components of the resulting PDU.

  • Fix to MsgAndPduDispatcher.sendPdu() to clean up request queue on pysnmp-level processing failure.

  • Fix to SNMPv1/v2c message processing subsystem to make it serving unique PDU request-id’s in both outgoing and incoming confirmed and response PDU types. Duplicate request-id’s in unrelated PDUs may cause cache errors otherwise.

  • Fix to licensing terms of multiple twisted backend modules to make the whole pysnmp package licensed under BSD 2-Clause license. This change has been explicitly permitted by the original modules authors.

  • Fix to asyncore-based transport not to use asyncore’s cheap inheritance from socket object what caused warnings.

  • Fix at NotificationOriginator to make is using MibInstrumentationController when expanding Notification OBJECTS into Managed Objects Instances.

  • Missing wrongLength and wrongEncoding SMI errors added.

  • Fix to file descriptor leak at MibBuilder.

  • Fix to rfc2576.v2ToV1() to ignore impossible errorStatus.

  • Fix to rfc2576.v1ToV2() to reset ErrorStatus==noSuchName on proxying.

  • Fix to smi.builder to explicitly fail on any MIB file access error (but ENOENT) and raise IOError uniformly on any directory/egg access failure.

  • Fix to infinite loop at config.delV3User().

Revision 4.2.5, released on Oct 02, 2013#

  • License updated to vanilla BSD 2-Clause to ease package use (

  • A dozen of lightweight Twisted-based example scripts replaced more complex example implementations used previously.

  • SNMP Proxy example apps separated into a larger set of more specialized ones.

  • Most of Command Generator examples re-pointed to a live SNMP Agent at to ease experimentation and adoption.

  • Multithreaded oneliner CommandGenerator example added.

  • Packet-level SNMP API (pysnmp.proto.api) getErrorIndex() method can now be instructed to ignore portentially malformed errorIndex SNMP packet value what sometimes happens with buggy SNMP implementations.

  • Standard SNMP Apps and built-in proxy now ignores malformed errorIndex value.

  • Built-in logging now includes timestamps.

  • Multi-lingual capabilities of all CommandGenerator & NotificationOriginator apps re-worked and improved. For instance it is now it’s possible to run getBulk() against a SNMPv1 Agent invoking built-in SNMP Proxy behind the scene.

  • The $PYSNMP_MIB_DIR & $PYSNMP_MIB_DIRS & $PYSNMP_MIB_PKGS path separator made platform-specific.

  • Change to rfc2576.v1tov2() logic: errorStatus = noSuchName is now translated into rfc1905.noSuchObject exception value for all var-bindings at once. Although RFC2576 does not suggest error-status -> v2c exception translation, historically pysnmp used to perform it for a long time so we can’t easily stop doing that.

  • Exception re-raising improved at MibInstrumController.flipFlopFsm() and asynsock/twisted dispatchers so that original traceback is preserved.

  • A single instance of transport dispatcher can now serve multiple receivers (identified by IDs) chosen by a public data routing method.

  • SnmpEngine.[un]registerTransportDispatcher() methods now accept optional receiver ID token to be used by transport dispatcher’s data router. This allows for multiple SNMP engines registration with a single transport dispatcher.

  • Distribute is gone, switched to setuptools completely.

  • The snmpCommunityTable row selection improved to follow RFC2576, clause 5.2.1.

  • Asyncore-based dispatcher attempts to use poll() whenever available on the platform. It would help handling a really large number (>1024) of file descriptors.

  • AsynCommandGenerator.makeReadVarBinds() generalized into a new makeVarBinds() method which replaces somewhat redundant code at setCmd() and AsynNotificationOriginator.sendNotification().

  • AsynCommandGenerator.uncfgCmdGen() & AsynNotificationOriginator.uncfgCmdGen() methods now accept optional authData parameter to remove specific entries from LCD. This can be useful for modifying security parameters for specific securityName.

  • SNMP credentials management reworked to separate userName from securityName in snmpCommunityEntry and usmUserEntry tables. Changes made to addV1System(), addV3User() functions as well as to their oneliner’s wrappers.

  • The contextEngineId parameter of config.addV3User() and auth.UsmUserData() renamed into securityEngineId as it’s semantically correct

  • Oneliner UsmUserData() and CommunityData() classes now support clone()’ing to facilitate authentication data management in user applications.

  • Oneliner transport target classes now support the getTransportInfo() method that returns network addresses used on protocol level.

  • Oneliner CommandGenerator.getNext() & .getBulk() methods now support the maxCalls kwarg to limit the maximum number of iterations to perform.

  • The config.addSocketTransport() helper renamed into config.addTransport() and improved by automatically instantiating compatible TransportDispatcher making it dispatcher-agnostic. As an additional bonus, application may not call registerTransportDispatcher() as it would be called by addTransport().

  • The SnmpV3MessageProcessingModel.getPeerEngineInfo() method is implemented to communicate discovered peer SNMP engine information to SNMP apps what can be used for fine usmUserTable configuration.

  • AsynNotificationOriginator.cfgCmdGen() does not take into account securityModel & securityLevel when reducing LCD access via addTrapUser(). This improves LCD consistency on sparse add/del operations but also does not let you to configure different securityModels per securityname at VACM though the cfgCmdGen() wrapper.

  • MIB builder traceback formatting and reporting improved.

  • SNMP Engine object now has a snmpEngineID attribute exposed.

  • Fix to inet_ntop()/inet_pton() support on Windows at TRANSPORT-ADDRESS-MIB.

  • Fix to usmUserSecurityName table column implementation – automatic value generation from index value removed.

  • Fix and significant logic rework of snmpCommunityTable to make it working in both Generator and Responder modes and better follow RFC2576 requirements on sequential entries lookup and selection. As a side effect, untagged snmpCommunityTable entries will not match tagged snmpTargetAddrTable entries and vice versa.

  • Fix to Twisted-based NotificationOriginator to make it serving INFORMs again.

  • Fix to rfc2576.v1tov2() logic: errorStatus = noSuchName is now translated into rfc1905.noSuchObject exception value for all var-bindings. Although this is not mentioned in RFC, it looks as a more consistent approach.

  • Fix of rounding error to base I/O dispatcher’s next timer call calculation.

  • Explicit twisted dispatcher’s timer resolution (of 1 sec) removed to make use of global default of 0.5 sec.

  • Fix to twisted/udp non-default local endpoint binding features. Common socket (‘host’, port) notation is now supported.

  • Fix to Twisted-based transport to make it closing UDP port / UNIX pipe on shutdown.

  • Fix to Twisted-based dispatcher not to close transport on unregistration at dispatcher as transports can potentially be reused elsewhere.

  • Fix to asyncore-based transport to work only with AsynsockDispatcher’s socket map and not to touch default asyncore’s one. The latter have caused dispatcher/transport restarting issues.

  • The delV3User() function improved to drop all rows from USM table that were cloned from the target one.

  • Fix to exceptions handling at MsgAndPduDispatcher.sendPdu() to avoid sendPduHandle miss (followed by system crash) on cache expiration run.

  • Break cyclic references at CommandResponder and NotificationReceiver apps through close() method.

  • Fix to octet string typing at 3DES codec (used to throw an exception).

  • Fix to SnmpAdminString, SnmpTagList, SnmpTagValue types to make them supporting UTF-8 initializers.

  • Fix to v1/v2c message processing module which used to refer to a bogus stateReference in some cases what causes SNMP engine crashes.

  • Fix to IPv6 transport to zero ZoneID, FlowID and ScopeID components sometimes coming along with incoming packet.

  • Fix to SNMPv1 MP module to pass stateReference to registered app on unconfirmed notifications reception (to let NotificationReceiver Apps browsing request details). (transport information at the moment) at SNMP engine.

  • Asyncsock sockets now configured with SO_REUSEADDR option to fix possible Windows error 10048.

  • Gracefully handle malformed SnmpEngineID at USM coming from SNMPv3 header.

  • Typos fixed in error-status constants at CommandResponder

  • Missing import added to oneliner auth module.

  • Cosmetic changes to v3arch example scripts.

Revision 4.2.4, released on Jan 30, 2013#

  • SNMPv3 high-level and native API examples reworked and extended to cover many use cases.

  • The missing functionality of NOTIFICATION-TYPE objects being looked up at local Management Instrumentation and attached to TRAP/INFORM message by Notification Originator is now fully implemented.

  • The missing functionality of passing Response PDU contents of INFORM request is now implemented at Notification Originator app. The return value of NotificationOriginator.sendNotification is now a composite object that includes errorStatus, errorIndex and varBinds.

  • The missing functionality of passing lookupNames & lookupValues params to Notification Originator is now implemented. It may make sense for INFORMs.

  • The missing functionality of passing contextName to oneliner version of NotificationOriginator.sendNotification is now implemented.

  • Oneliner example apps now include cases where non-default SNMP ContextEngineId/ContextName/SecurityEngineId is used.

  • The contextName parameter of SnmpContext.getMibInstrum made optional.

  • AbstractMibInstrumController class added as a base class for all possible kinds of Management Instrumentation controllers.

  • Report package version on debugging code initialization.

  • MibInstrumController.getMibBuilder() added.

  • I/O sockets buffer sizes made configurable, minimum default is now forced to be no less than 2**17 (to fit two huge datagrams).

  • Catch possible exceptions on pyasn1 encoder invocation.

  • VACM modules converted from a function into an object to let it keep state (caches) in the future.

  • Unnecessary MibSource explicit initialization calls removed at MibBuilder.

  • Example configuration for Net-SNMP’s snmptrapd added.

  • Cast additionalVarBinds into ObjectIdentifier type at NotificationOriginator.sendNotification()

  • Standard SNMPv3 Apps hardened to catch protocol-related exceptions and report them as errorIndication’s.

  • Catch and mute possible failure of getsockname(), that seems to happen on Windows only so far.

  • Memory leak fixed at oneliner cache of already configured targets.

  • Fixes to at AsynNotificationOriginator.sendNotification() to make a) the notificationType param mandatory b)t e varBinds param really optional

  • Fixes to ContextEngineId/ContextName support at the oneliner API: now both items should be passed to request PDU through Cmd() request initiation method, the items of authData object should be used only for LCD configuration.

  • Fix to MibVariable handling of the MIB, <empty-symbol> initializers.

  • Fix to outgoing queue processing order at socket transport. Now it’s a FIFO discipline rather than LIFO.

  • Fix to NotificationOriginator’s additionalVarBinds parameter - it is not mandatory anymore with the oneliner API. Also additionalVarBinds defaulted value changed from None to () meaning no var-binds.

  • Attempt to convert Windows style EOL into UNIX ones in MIB source modules appeared to be unnecessary and even destructive to modules data in some cases. So the conversion code removed altogether.

  • Fix to isAccessAllowed() error handling at NotificationOriginator. System used to crash on access denied condition.

  • Fix to NotificationOriginator to make it use system uptime and trap OID values from SNMP engine’s instrumentation rather then from SNMP context.

  • Fix a couple of bugs at MibTable* logic involved for table instances creation.

  • Fix to Management Instrumentation code to handle cases of non-initialized or not-compliant-to-constraints Managed Objects Instances.

  • Fix to Management Instrumentation code to make table row removal through SNMP working again. Wrong method (instumClone) was probed at terminal MIB nodes values instead of the right one (setValue).

Revision 4.2.3, released on Sep 06, 2012#

  • SECURITY FIX: USM subsystem did not verify securityLevel of a request to an authoritative SNMP engine against auth/priv protocols configured for the user in question. That allowed unauthenticated/unciphered access to pysnmp-based Agent even if USM user is configured to provide one.

  • Oneliner [Asyn]CommandGenerator now supports optional keyword args lookupNames, lookupValues that enable response OID / value looked up at MIB and reported as a MibVariable container object carrying relevant MIB info.

  • Oneliner [Asyn]CommandGenerator now supports symbolic MIB object names to be passed within a MibVariable container object which would do a deferred MIB lookup for name resolution. This is a new and preferred API which obsoletes the tuple-based one (it is still suppored though).

  • Oneliner CommandGenerator’s class attributes lexicographicMode, maxRows and ignoreNonIncreasingOid moved to optional keyword args of nextGen() and bulkGen() methods.

  • IPv6/UDP and Local Domain Socket transport interfaces added to the oneliner API.

  • Mib Instrumentation subsystem re-worked to replace excessive MibNode’s smiCreate()/smiWrite()/smiDestroy() methods with MibScalarInstance’s getValue()/setValue()

  • MibTree.readTest[Get]Next() reworked to be called uniformely so user could tap on these methods at any level of the MIB tree.

  • MibTableColumn.getNextNodeWithValue() unpublished API method obsoleted and removed for clarity.

  • Hex dumps of binary parts of the protocol added to ease system operations analysis.

  • SnmpEngineId autogeneration does not call DNS resolver but uses local hostname not to depend upon local IP availability and performance.

  • Example apps reworked, additional SNMPv3 auth/priv protocols and transports added.

  • Package version is now available as __init__.__version__ and it is in-sync with distutils.

  • Package meta-information updated.

  • The’s made non-empty (rumors are that they may be optimized out by package managers).

  • Multiple fixes to UNIX domain socket transport to make it fully operational again.

  • Use sysUpTime value whenever it is included in Notification PDU, otheriwese resort to SNMP engine uptime reading.

  • SNMPv2c Message is now defined in what matches standard definition.

  • Types defined within SNMPv1/v2c data structures ( moved to module scope to become accessible by wrapper routines ( This is used for setting strictly typed default values to corresponding SNMP data structures.

  • The obsolete and unpublished MibInstrumController.readVarsFast() method removed for API clarity.

  • MibBuilder now distinguishes case of MIB modules filenames even if underlying OS does not.

  • LCD configuration caching is implemented at pysnmp.entity.rfc3413.config that improves performance of repetitive calls by 10% and might hugely improve NotificationOriginator’s performance when working on a large number of targets.

  • A caching maps implemented at rfc2576 subsystem to speed-up communityName to/from securityName resolution. The also makes transport tags processing better compliant to the standard.

  • Community and Transport tags processing changed at the oneliner interface to make the whole mechanism more compliant with the standard. Most importantly, it is now possible to tag authentication and transport information separately.

  • The NoSuchInstanceError exception class is no more inherits from NoSuchObjectError to make class hierarchy closer to SNMP specification which states that these errors are separate and independent.

  • The Next & BulkCommandGenerator’s split onto single-run and iterative impementations. The former just process a single interaction and complete while the latter run as many interactions as user callback function indicates to.

  • The pysnmp.entity.rfc3413.mibvar module is now obsolete by pysnmp.entity.rfc3413.oneliner.mibvar featuring basically the same features but within a stateful, dedicated object.

  • Auth & target configuration container classes moved to their separate modules at oneliner API.

  • The notificationType parameter of AsynNotificationOriginator.sendNotification made defaulted to reflect its optional nature.

  • Oneliner UsmUserData, UdpTransportTarget, Udp6TransportTarget instances are not hashable anymore as they are intended to act more like a data structure than object.

  • Built-in debugger now supports negating debugging categories.

  • An async/ example script added.

  • Fix to MIB data reading routine to make it working with possible Windows end-of-line’s.

  • Fix to CommandGenerator’s SNMPv3 engine autodiscovery algorithm when retryCount is administratively set to 0.

  • Fix to Notification Originator to make it communicating a single sendPduHandle to an application even when multiple INFORMs are triggered and processed by a single call by way of transport tagging feature.

  • Fix to rfc2576:processIncomingMessage() to take SecurityModel into account when lookup up SecurityName by CommunityName. This allows mixed SNMPv1/v2c communication with the same target.

  • Fix to internal MessageProcessing and SecurityModel timers so they become dependant on system timer resolution.

  • Fix to v1.PDUAPI.setDefaults() method that used to set wrongly typed time-stamp component.

  • Fix to IPv6 address handling to prevent system from crashing whilst running Python3.

  • Fix to SNMPv2 exception objects translation into SNMPv1 PDU and NEXT OIDs calculation.

  • Fix to MibTree class to properly report noSuchObject & noSuchInstance SNMP special values.

  • Fix to libsmi2pysnmp tool to make it working again in Python < 2.7

  • Fix to exception handling at decodeMessageVersion() caller to prevent ASN.1 parsing errors crashing the whole app.

  • Fix to GenericTrap type processing at rfc2576:v1Tov2c() which used to crash the whole SNMP engine.

  • Fix to [possibly uninizilaized] pyasn1 objects printouts at MibInstrumController.__indexMib()

  • Fix to maxSizeResponseScopedPDU calculation at rfc3414/

  • Dedicated ‘withmib’ example set is obsolete and removed.

  • Another SNMP proxy example app added (

  • Fix to MIB modules loading code to make it using __import__() properly. This also makes pysnmp working again with Python 3.3rc0.

  • Typo fix to snmpInASNParseErrs MIB instance object.

  • Typo fix to errind.EngineIdMismatch class and its instance.

Revision 4.2.2, released on Apr 21, 2012#

  • Oneliner CommandGenerator can now limit the number of SNMP table rows returned by nextCmd()/bulkCmd() methods.

  • Oneliner CommunityData configuration object can now be initialized with community name only, security name will be chosen automatically.

  • Oneliner LCD configuration routines reworked towards clarity. The side-effect of this change is that repetitive oneliner call with the same securityName and different configuration options will only honor the first settings. Previous implementation would override older settings.

  • Transport dispatcher now provides its own time expressed in fractions of second. SNMP engine uses this notion of time for handling requests timeout to make packet flow time bound to async I/O core operations rather than to real time.

  • The libsmi2pysnmp tool improved to handle incomplete SMI v1->v2 conversion performed by smidump. The remaining core SMIv1 modules excluded from the core MIB set.

  • The pyasn1 constraint and enumeration objects put into ASN1-* MIB modules what appears to be more in-line with SMI. Existing MIB modules as well as libsmi2pysnmp tool corrected accordingly.

  • SMIv1 MIB modules (including RFC1155 and RFC1213) were moved to pysnmp-mibs as pysnmp is SMIv2-based.

  • The MibBuilder.importSymbols() now takes optional kwargs and push them into MIB modules globals(). This is to facilitate passing user infomation, such as DB connection handler, to MIB module namespace so it could be used by ManagedObjects implementations.

  • When running on Python3, SMI will re-raise exceptions with the original traceback for easier diagnostics.

  • Out of PYTHONPATH MIB paths now supported.

  • Added pyasn1 decoder failures diagnistics in debug mode.

  • Fix to non-MT-safe class attributes at SNMPv3 MP & SEC modules.

  • Fix to ContextName handling in bytes form whilst running Python3. Data mismatch error would return otherwise.

  • Fix to SNMPv3 MP peer engine ID discovery not to learn and use user-specified ContextEngineId.

  • Fix to socket.error processing at Py3 on Windows.

  • Fix to oneliner GETNEXT/GETBULK implementation to properly support ignoreNonIncreasingOIDs option.

  • Fix to setEndOfMibError()/setNoSuchInstanceError() at v1 PDU not to loose errorIndex.

  • Fix to api.v2c.getVarBindTable() to ignore possible non-rectangular GETBULK response tables.

  • Fix to oneliner getnext/getbulk response table rectangulation procedure to gracefully handle an empty column condition.

  • Fix to legacy MibBuilder.getMibPath() to prevent it from missing .egg-based components in path.

  • Fix to oneliner configuration routine that used to implicitly tag SNMPv1/v2c auth and transport LCD rows what resulted in huge delays when processing incoming messages with large number of peers configured.

  • Fix to UDP6 transport handling at rfc2576 security module.

  • Fix to SnmpEngineID value autogeneration (used to fail on Mac).

  • SNMPv2-SMI.ObjectType.__repr__() fixed to do a repr() on its components.

  • All SNMPv2-SMI.MibNode-based objects, once exported to a mibBuilder, will carry an embedded label symbol.

  • Exlicit repr() calls replaced with ‘%r’

  • Fix to error processing at GETNEXT & GETBULK apps response handlers.

  • Fix to libsmi2pysnmp to make it supporting long (256+) list of function params.

  • Fix to libsmi2pysnmp to support inheritance of MIB types.

Revision 4.2.1, released on Nov 07, 2011#

  • Support string OIDs at one-liner API.

  • Code quality of libsmi2pysnmp tool improved, MIBs re-built.


  • v1arch example added

  • Major overhawl for Python 2.4 – 3.2 compatibility:

    • get rid of old-style types

    • drop string module usage

    • switch to rich comparation

    • drop explicit long integer type use

    • map()/filter() replaced with list comprehension

    • apply() replaced with var-args

    • dictionary operations made 2K/3K compatible

    • division operator made 2K/3K compatible

    • sorting function now operates on key

    • iterators returned by some funcs in py3k converted to lists

    • exception syntax made 2K/3K compatible

    • tuple function arguments resolved to scalars to become py3k compatible

    • BER octetstream is now of type bytes (Py3k) or still string (Py2k)

Revision 4.1.16d, released on Sep 22, 2011#

  • Fix to SNMPv1 Trap PDU agentAddress setter shortcut method.

Revision 4.1.16c, released on Aug 14, 2011#

  • Missing module import fixed in privacy subsystem

Revision 4.1.16b, released on Aug 13, 2011#

  • Oneliner CommandGenerator can now optionally ignore non-increasing OIDs.

  • Default CommandResponder now skips non-compliant (Counter64) values when responding to a v1 Manager.

  • Fix to state information handling at CommandResponder app.

  • Fix to Twisted reactor shutdown condition.

  • Fix to distutils dependencies syntax.

Revision 4.1.16a, released on Mar 17, 2011#

  • Extended Security Options (3DESEDE, AES192, AES256) privacy protocols implemented.

  • The error-indication codes moved from literals to objects for reliability and clarity

  • Fix to v1.TrapPDUAPI.getVarBinds() to address PDU component at the right position.

  • Fix to rfc1902.Bits initialization from named bits sequence.

  • Fix to MIB builder by-extension module filtering code to cope with .pyw files.

  • Internal caches structure improved.

  • Sync versions of oneliner apps split off async implementation for clarity.

  • Randomize initial in various numeric sequences.

  • MsgAndPduDsp expectResponse parameters passing reworked.

  • GetNext/GetBulk response processing logic moved to getNextVarBinds()

  • Changes towards performance improvement:

    • all dict.has_key() & dict.get() invocations replaced with modern syntax (this breaks compatibility with Python 2.1 and older).

    • introduce the MibInstrumControlle.readVarsFast() method (which skips the “testing” phase of MIB value readin) for dealing with internal configuration (LCD).

    • default debug.logger is now just a zero value instead of an object what saves big on frequent calls

    • SNMPv2-SMI columnar indices <-> index values conversion code optimized.

    • pre-compute and re-use some of ASN.1 structures.

    • avoid setting PDU defaults to save on unnecessary initialization.

    • skip ASN.1 types verification where possible.

    • at oneliner Command Generator, avoid looking up pure OID arguments at MIB as it’s pointless but takes time.

    • cache MIB columnar objects instance ID <-> symbolic index representation mapping

Revision 4.1.15a, released on Dec 13, 2010#

  • SNMP Proxy example added.

  • End-of-MIB condition detection reworked what caused backward incompatibility at v1arch GETNEXT API. Previous pysnmp versions used value = None in var-binds as returned by getVarBindTable() API method. This version uses rfc1905 exception values (v2c/v3) or pyasn1 Null (v1). Built-in GETNEXT/GETBULK apps now do not require user to track end-of-mib conditions anymore – this is now done automatically.

  • CommandResponder API now supports async mode of operation.

  • SNMP exception values now exported from rfc1905 module, and made pretty printable.

  • Lexicographic walking mode is now supported at oneliner CommandGenerator.

  • ContextEngineId&ContextName parameters passing implemented at v3arch oneliner API.

  • Multiple instances of the same transport domain now supported.

  • Initial snmpEngineId value generation improved not to accidentally collide within an administrative domain.

  • MibTableColumn instances now build value-to-column-instance map to speedup by-value search.

  • SNMPv2-CONF::AgentCapabilities macro implemented.

  • The libsmi2pysnmp tool handles some more MACROs.

  • Void access control module implemented to let apps disabling [default] VACM.

  • Allow standard SNMP apps to choose access control method to use.

  • Twisted-based CommandResponder example added.

  • Fix/rework of Twisted GETNEXT/BULK CommandGenerator callback API to make it simpler and uniform with other CommandGenerators

  • Fix to SNMPv3 security module to store peer SNMP engine timeline only if taken from an authenticated message. Prior to this fix SNMP engine was not been protected from spoofing.

  • Fix to $SMIPATH initialization at build-pysnmp-mib.

  • Fix to maxSizeResponseScopedPDU calculation.

  • Fix to Next/Bulk CommandGenerators to catch a non-increasing OID error condition (what prevents looping).

  • Fix to Opaque value tagging at rfc1155.Opaque type.

  • Fix to handle (fail gracefully) zero-length user password.

  • Fix to SNMP error propagation at Twisted driver (SF tracker ID #3054505).

  • Fix to Agent-role snmpEngineId discovery procedure that allows authenticated ReportPDU generation.

  • Fix to SNMPv1 PDU handling at CommandResponder & NotificationReceiver apps.

  • Fix to CommandResponder app to skip Counter64 SMI values when responding to SNMPv1 Manager.

  • Fix to protocol translator code (rfc2576) to handle Counter64 type in v2c-to-v1 PDU translation.

  • Fix to non-response var-binds translation in rfc2576.v2ToV1().

  • Fix to wrong exceptions used in pysnmp/entity modules.

  • Fix to noauth/nopriv security module so that it would not crash SNMP engine if called accidentally.

  • Fix to CommandResponder not to return out-of-range errorIndex along with genErr

  • Fix to GETBULK CommandResponder to do a by-column MIB walk, not by-raw.

  • Fix to getVarBindTable() API function logic.

  • Fix to example Manager scripts to use errorIndex when available.

  • Fix to dummy encryptData()/decryptData() API

  • Fix to oneliner GETBULK table collection code to make it stripping uneven rows off table tail.

Revision 4.1.14a, released on Jul 15, 2010#

  • Fix to maxSizeResponseScopedPDU calculation at USM security module: now more precise and robust against screwed values on input.

  • Fix to MIB loading logic that used to load same-name modules at disticts search paths on each loadModules() call.

  • Fix to AsynsockDispatcher.runDispatcher() to make use of optional non-default select() timeout value.

  • AbstractTransportDispatcher now allows user application registering multiple timer callbacks each with dedicated call period.

  • Asynsock mainloop default idle period reduced to 0.5 sec for better timer resolution.

  • Fix to SNMPv1->SNMPv2c error status handling at proxy module. This defect may have caused an infinite loop on a multiple var-bind SNMPv1 GetNext operation.

  • Fix to contextName processing at config.addV1System – typo rendered passed contextName not committed into LCD.

  • Fix to unknown ContextName exception handling at CommandResponder App.

  • config.addVacmUser() now accepts an optional contextName what makes it usable for configuring multiple contextName-bound bases of Managed Objects to SnmpEngine.

  • MP pending states cache management re-worked so that SNMP engine will now handle an unlimited number of pending request/responses.

  • Fix to SNMP discovery procedure: include ContentName in SNMP discovery messaging.

  • Many fixes to AES crypto code that makes it actually working.

  • Fix to SNMPv2-SMI createUndo operations.

  • Fix to INFORM sending error handling at oneliner.

  • Fix to mismatched response PDU handling at CommandGenerator application.

  • Debug category ‘app’ (for Application) added to facilitate Standard SNMP Applications debugging.

  • The retryCount semantic of CommandGenerator application changed to include sole retries and do not include initial request. Thus, retryCount=1 will now send up to two packets, not just one as it used to be.

  • Debugging printout now escapes non-printable characters.

Revision 4.1.13a, released on Feb 09, 2010#

  • UDP over IPv6 transport implemented.

  • Fix to MIB tree walking code that used to fail on table columns where indices have identical leading parts.

  • SNMPv1/v2c snmpCommunityTransportTag-based imcoming message filtering implemented (rfc2576).

Revision 4.1.12a, released on Dec 03, 2009#

  • API versioning retired (pysnmp.v4 -> pysnmp).

  • MIB loading mechanics re-designed to allow ZIP import.

  • MIB loader supports code objects (py[co])

  • Installer now uses setuptools for package management whenever available.

  • The libsmi2pysnmp tool improved to build constraints of more than 256 items (Python has a limit on the number of function params).

  • Missing SNMPTrap PDU API implemented at proto.api.v2c, RFC2576 proxy code reworked.

  • Fix to sysUpTime OID at SNMPv2 TRAP PDU.

Revision 4.1.11a, released on Aug 21, 2009#

  • Twisted integration implemented.

  • Attempt to use hashlib whenever available.

  • Fix to oneliner Manager code on < Python 2.4.

  • Let NotificationReceiver and CommandResponder Apps browsing request details (transport information at the moment) at SNMP engine.

  • Fix to config.addV1System() to allow multiple systems to co-exist in LCD.

  • Fix to wrongly succeeding user-parameters-by-community-name searching code in rfc2576 processIncomingMsg() method.

  • Do sanity checking on PYSNMP_MODULE_ID, Groups and Notifications in libsmi2pysnmp (SF bug #2122489).

  • Fix to oneliner Notification Originator that sometimes used to send multiple requests at once.

  • Oneliners LCD names generation code reworked to avoid accidental clashes.

  • Fix and re-work of sysUpTime value management in LCD.

  • Fix to pending inform request data caching in mpmod/ – previous code led to cache data corruption on multple outstanding requests.

  • In SMI configuration wrapper functions, catch access to non-configured entries and raise an exception.

  • Allow multuple callback timer functions in all transport dispatchers.

  • Fix to libsmi2pysnmp code to preserve more underscored object names and to guess the right type between indistinguishable ObjectGroup & NotificationGroup

  • Fix to MibScalarInstance value setting logic - previous code failed when modifying the same OID multiple times within a single SET operation.

  • Minor usability improvements to tools/build-pysnmp-mib.

  • Made MIB objects unexport feature operational.

Revision 4.1.10a, released on May 25, 2008#

  • Internal MIB indexing method __indexMib() unmangled to facilitate setting up mutex there for sharing MIB stuff between threads.

  • Fixed broken IpAddress value handling in SET operation.

  • Broken MibBuilder.unloadModules() method now works.

  • Use getLabel() SMI object method when building MIB tree (in in addition to direct attribute access for clearer object protocol.

  • The MIB building tools updated to match significantly improved smidump tool (libsmi version > 0.4.5).

  • Made libsmi2pysnmp tool optionally building MIB text fields into pysnmp MIB code (enabled by default) and MibBuilder conditionally loading them up (disabled by default).

  • SnmpEngine and MsgAndPduDispatcher constructors now optionally take msgAndPduDspr and mibInstrumController class instances respectively to facilitate these objects sharing within a process.

  • Unique integers, for various parts of the system, are now generated by a module. This fixes possible issues with duplicate request IDs and handlers.

  • Built-in MIBs re-generated to include text fields.

Revision 4.1.9a, released on Nov 28, 2007#


  • At onliner CommandGenerator, close transport on destruction to prevent socket leak. Implicit async transports registration at default asyncore’s socket map has been disabled to avoid side effects.

  • Fix to rfc2576.v1ToV2c() PDU converter to perform noSuchName error code translation.

  • Fixes to Notification PDU conversion code at rfc2576 in part of snmpTrapOID handling.

  • Fix to nonRepeaters object use as sequence slicer (must be int) at cmdrsp.CommandResponderApplication

  • Make AsynsockDispatcher using its own socket map by default for threading safety. This will break asyncore apps that rely on pysnmp sharing the same socket map with them. A solution would be to either set asyncore map to pysnmp (AsynsockDispatcher.setSocketMap()) or pass pysnmp map (AsynsockDispatcher.getSocketMap()) to asyncore.

  • Fix to response timeout roundup bug at CommandGenerator and NotificationOriginator code.

  • Oneline configuration classes made hashable to prevent memory leaks when committing them into CommandGenerator/NotificationOriginator internal repository.

  • Security information is now released properly in all MP modules. This might fix a significant memory leak.

  • Typo fix to rfc3411 confirmed class PDU members.

Revision 4.1.8a, released on Aug 14, 2007#


  • SMI/dispatcher timeout conversion multiplier is actually 100 (1/100 sec) rather than 1/1000. This fix affects timeouts specified through SMI.

  • __repr__() implemented for UdpTransportTarget, CommunityData, UsmUserData in oneliner module.

  • Automatically initialize table index values on table management operations (SF bug ID #1671989).

  • Fix to carrier code: ignore BADFD socket error as it may happen upon FD closure on n-1 select() event.

  • Fix to MibBuilder.setMibPath() to preserve previously loaded modules intact. Otherwise loadModules() called after setMibPath() might fail with ‘MIB file not found in search path’ exception.

  • Fix to oneliner classes that now invoke unconfiguration methods on destruction. This might have caused memory leaks.

  • Automatically initialize SNMP-USER-BASED-SM-MIB::UsmUserSecurityName columnar object instance on creation, as stated in DESCRIPTION (SF tracker ID #1620392).

  • Fix to USM timeframe arithmetics (SF bug #1649032).

  • VACM shortcuts merged into universal add/delVacmUser() to let notifications and requests to co-exist for the same user.

  • At oneliners, build LCD tables keys from a hashed mix of input parameters to make sure these automatic entries won’t interfere or exceed constraints on keys values.

  • Made use of notificationType parameter of the sendNotification method in NotificationOriginator applications. This parameter used to be ignored in the past. Note, that previously used (and ignored) syntax has been changed in an incompatible way.

  • Allow plain Python values in setCmd() and sendNotification() methods in CommandGenerator and NotificationOriginator applications respectively.

  • Multi-target oneliner API-based example script added.

  • Ignore more socket errors in datagram-type async socket code.

  • AES cipher now supported (rfc3826).

  • Fix to messed up tagIDs of noSuchInstance and noSuchObject types.

  • SET Command Responder fixed to obscure access to non-existing variables by returning notWritable error (SF bug #1764839).

  • AsynsockDispatcher.setSocketMap() method added to facilitate pysnmp transport integration into third-party asyncore-based applications.

  • Fix to errorIndex generation at CommandResponder application, the value should be a one-based.

Revision 4.1.7a, released on Feb 19, 2007#


  • Low-level debugging facility implemented.

  • Support UdpTransportTarget timeout and retries parameters in oneliner API.

  • Fix to snmpTrapOID construction at …proxy.rfc2576.v1ToV2() function.

  • Fix to MibViewController.getNodeName() to take MIB module name into account (SF bug #1505847).

  • Do explicit check for Counter32,Unsigned32,TimeTicks,Counter64 value types in MibTableRow index conversion and in TextualConvention.prettyPrint() methods (SF bug #1506341). Handle Bits in indices as RFC2578 suggests.

  • Apply read-create column status to libsmi2pysnmp-generated code whenever MIB text specifies that (SF bug #1508955).

  • Honor and apply DISPLAY-HINT specification when building TextualConvention class at libsmi2pysnmp.

  • Managed Objects Instances files (smi/mibs/instances/) are now double-underscore prefixed to make them imported explicitly by these prefixed names. They used to be imported as a side-effect of Managed Objects files import what is way too hackerish.

  • The libsmi2pysnmp now supports future libsmi bugfix that would generate “ranges” subtree along with the legacy and ambiguous “range” one.

  • SMI support for fixed-length string indices implemented (SF bug #1584799, #1653908).

  • Managed Object Instances may now have smiRead, smiWrite, smiCreate methods to support specific value mangling. These methods, if present, would be invoked from SNMP [Agent] core instead of conventional clone() method. The reason is to separate trivial value duplication from specific Instance value mangling that may have Agent-specific side effects (such as RowStatus).

  • MIB table row destruction now works (SF bug #1555010).

  • LCD unconfiguration functions for oneliners implemented (SF bug #1635270).

  • unloadModules() and unexportSymbols() implemented at MibBuilder

  • Notification type PDU proxy code fixed to produce symmetrical conversion.

  • Various SNMP engine-internal caches expiration implemented.

  • SMI-level access control now takes effect only if AC object is passed to MIB instrumentation API.

  • LCD management code now uses generic MIB instrumentation features.

  • Fix to oneliner manager code to have individual UdpSocketTransport instance per each SnmpEngine. Multithreaded apps might fail otherwise. (SF bug ID #1586420).

  • Exclude the PYSNMP_MODULE_ID symbol from MIB view index, as it may get resolved into OID label instead of actual MIB object name.

  • Memory leak fixed in indices.OidOrderedDict implementation.

  • Fix to VACM shortcuts to let notifications and requests to co-exist for the same user otherwise.

  • Fix to …oneliner.cmdgen.UsmUserData to support non-default ciphers.

  • USM now uses local notion of snmpEngineBoots/Time when authoritative and cached estimate otherwise. Also, a security fix applied to to USM time-window verification (SF bug #1649032).

  • Fix to notification objects resolution code at NotificationOriginator.sendNotification()

  • Do not raise securityLevel for USM error reports that lacks user information, as these reports could never be ciphered (SF bug #1624720).

  • Non-default BULK PDU params now actually applied.

  • SnmpEngineID default value generation algorithmic function changed to allow multiple SNMP engines running on the same host.

  • Documentation updated.

  • A handful of minor fixes applied (SourceForge tracker IDs #1537592, #1537600, #1537659, #1548208, #1560939, #1563715, #1575697, #1599220, #1615077, #1615365, #1616579).

Revision 4.1.6a, released on May 25, 2006#


  • pysnmpUsmSecretAuthKey and pysnmpUsmSecretPrivKey length increased up to 256 octets. There seems no limit on this in RFC, though.

  • A workaround for probably broken Agents: SNMPv3 Manager code defaults ContextEngineId to SecurityEngineId whenever ContextEngineId is not reported by authoritative SNMP engine on discovery.

  • Use empty PDU in engine-discovery report at mpmod/

  • MibBuilder.loadModules() now fails on missing MIB files.

  • MibBuilder.exportSymbols() now accepts unnamed objects (likely Managed Objects Instances)

  • SNMPv2-SMI.MibScalarInstance objects now support create*/destroy* Management Instrumentation methods to pass Columnar Object creation and removal events. MibTableColumn class invoke these methods accordingly.

  • Fix to AsynNotificationOriginator.asyncSendNotification() callback formal parameters

  • Initial VACM configuration implemented according to rfc3415 Appendix 1

  • tools/ split-up and re-implemented as tools/build-pysnmp-mib and pysnmp-mibs/tools/rebuild-pysnmp-mibs for better usability. These and libsmi2pysnmp scripts made installable.

  • Types/Notifications/Groups exportSymbols() call chunking implemented in tools/libsmi2pysnmp

  • Initial values specified to pyasn1 types to comply with latest pyasn1 API.

  • Documentation improved

  • Minor fixes towards Python 1.5 compatibility

Revision 4.1.5a, released on Nov 04, 2005#


  • Multi-lingual SNMP Trap/Inform Applications completed; examples added

  • SMI model re-designed to make a clear separation between Managed Objects and their specification (AKA Agent and Manager side)

  • SNMP SET Application support completed

  • Minor, though backward incompatible, changes to one-liner API

  • Many bugfixes

Revision 4.1.4a, released on Aug 16, 2005#


  • SHA-based authentication fixed and privacy implemented

  • …oneliner.cmdgen.UsmUserData constructor now takes authProtocol and privProtocol parameters in a backward incompatible manner.

Revision 4.1.3a, released on Jul 28, 2005#


  • rfc3413 applications API changes (related to callback function behaviour).

  • TransportDispatcher now provides “jobs” interface to clients for better control of dispatcher’s execution.

  • Many minor fixes.

Revision 4.1.2a, released on Jul 12, 2005#


  • Top-level application classes renamed into longer, self descripting names for clarity.

  • CommandResponder & NotificationOriginator applications now uses stand-alone SnmpContext for application registration.

  • Many minor fixes (inspired by testing on WinXP)

Revision 4.1.1a, released on Jun 29, 2005#


  • SNMPv3 code first published

  • SNMP engine and applications implemented on library level

  • Major re-design towards SNMPv3-style API.

Revision 4.0.2a, released on Mar 01, 2005#

  • Adopted to slightly changed asyncore API (as shipped with python 2,4)

Revision 4.0.1a, released on Nov 18, 2004#

  • Minor bug/typo fixes, mostly in example/ scripts.

Revision 4.0.0a, released on Nov 15, 2004#


  • Major re-design and re-implementation.

  • Rudimental API versioning implemented to let incompatible package branches to co-exist within the same Python installation.

  • SMI framework designed and implemented. This framework provides 1) various access to MIB data 2) a way to implement custom MIB instrumentation objects. There’s also a tool for building SMI classes from libsmi(3) output (smidump -f python).

  • ASN.1 subtyping machinery implemented. Now dynamic ASN.1 instances subtyping and quering becomes available. Previously, this has been done through Python classes inheritance what proved to be a wrong concept.

  • ASN.1 codecs framework re-designed and re-implemented aimed at a more consistent design and better performance. Highlights include abstract codec interface and serialized data caching (at encoder).

  • Asn1Item constraints machinery re-implemented based on Mike C. Fletcher’s design and code. Now various constrains are implemented as stand-alone objects serving interested Asn1Object derivatives through some abstract protocol (that’s probably the Decorator design pattern).

  • ASN.1 tagging facility re-implemented along the client-server design pattern. Besides this seems to be a more appropriate design, it allows an easier way for dynamic subtyping.