Net::SNMP Changes

RELEASE 6.0.1 SEP-09-2010

- Removed all occurrences of the "locked" attribute that was
  deprecated in Perl 5.12.0.
- Changed the test validating the presence of a monotonic time value
  to check for invalid implementations.
- The SNMPv3 contextEngineID and contextName are now stored as part
  of the request allowing for these values to be changed between

RELEASE 6.0.0 SEP-09-2009

- Substantial internal code cleanup was performed based upon the
  Perl::Critic module and the "Perl Best Practices" book.
- Added support for the Module::Build system for building, testing,
  and installing Perl modules.
- The translation logic for OCTET STRINGs now uses the definition of
  a DisplayString in RFC 2579 to determine if the octets are to be
  converted into a hexadecimal representation.
- The get_table() and get_entries() methods were refactored as part
  of the code cleanup.  The get_entries() method now handles "holes"
  in tables better and indexes with a value of zero.
- The inheritance structure of the Transport Domain objects was
  updated to reduce code duplication and increase maintainability.
- The resolution of IPv6 addresses was made more exhaustive.
- The handling of OBJECT IDENTIFIERs was made more efficient by 
  using [un]pack() with a BER compressed integer template. 
- Additional validation of the values passed to most methods is now
  performed and the error messages have been made more robust.
- The documented examples were updated based upon commonly asked
  questions (specifically Example 3 and Example 4).
- A Response-PDU with an error-status set to "noError" no longer
  generates an error when the error-index is non-zero, as decribed
  in Section 4.2.4 of RFC 3416.
- The function oid_lex_cmp() was added to provide for the
  lexicographical comparison of two OBJECT IDENTIFIERs.
- The error-status is no longer set for the exceptions noSuchObject,
  noSuchInstance, and endOfMibView when translation is not enabled.

RELEASE 5.2.0 OCT-20-2005

- Removed the dependency on the IO::Socket::INET and IO::Socket::INET6
  modules.  The IO::Socket module is now used for all socket objects.
- The port information can now be included as part of the transport
  address specified with the session() Transport Domain arguments.
- Added support for specifying the scope zone index for IPv6 addresses
  as described in RFC 4007 - "IPv6 Scoped Address Architecture".
- The default value for the agent-addr in SNMPv1 Trap-PDUs is now the
  IP address associated with the interface on which the trap will be

RELEASE 5.1.0 JUL-20-2005

- Support of the AES privacy protocol was updated to be compliant with
  RFC 3826 - "The Advanced Encryption Standard (AES) Cipher Algorithm
  in the SNMP User-based Security Model".
- Corrected an issue where any non-blocking SNMPv3 message queued prior
  to calling snmp_dispatcher() was sent with an empty contextEngineID. 
- The first SNMPv3 discovery message is again being sent with a zero-
  length msgUserName as suggested by RFC 3414.
- All sockets are now flagged as non-blocking to prevent a possible
  deadlock due to an interaction between recv() and select().
- The sending of messages is now bounded by the receive processing rate
  to avoid receive buffer overflows.
- The return value of select() is now checked for both "undef" and -1.
- The "usm.t" tests are now skipped if any of the non-core modules
  required by the Net::SNMP::Security::USM module are not present.

RELEASE 5.0.1 SEP-09-2004

- The module is now again functional with Perl 5.6.x.  Compensations
  were made for compatibility problems with the IO::Socket::INET and
  Math::BigInt modules packaged with Perl 5.6.x.
- The UDP/IPv6 and TCP/IPv6 Transport Domains are now functional when
  using version 2.0x of the IO::Socket::INET6 module.
RELEASE 5.0.0 JUL-20-2004 

- Added support for the UDP/IPv6 Transport Domain listed in RFC 3419.
- Support for the TCP/IPv4 and TCP/IPv6 Transport Domains was added
  as described in RFC 3430 - "SNMP over TCP Transport Mapping".  
- Optimizations were made to ASN.1 processing and preparation methods. 
- Corrected a possible memory exhaustion error with OCTET STRINGs that
  contain "printf" format characters. 
- The ASN.1 types associated with the ObjectSyntax values in the
  VarBindList can now be retrieved using the var_bind_types() method.
- The function snmp_type_ntop() was added for displaying ASN.1 types.
- The Net::SNMP::Dispatcher module now checks for select() errors.
- Passing the "-maxrepetitions" argument with a value of 1 or less
  to the get_table() or get_entries() methods instructs them to use 
  get-next-request messages instead of get-bulk-request messages. 
- The maximum allowed value for the maxMsgSize was reduced to 65535.
- The Perl modules for the non-default Transport Domains and Security
  Model are now loaded at runtime instead of compile time.

RELEASE 4.1.2 SEP-11-2003

- Removed an unintended dependency on the Crypt::Rijndael that would cause 
  SNMPv3 support to be unavailable and the "usm.t" tests to fail due to
  a "strict subs" error in Net::SNMP::Security::USM module.
RELEASE 4.1.1 SEP-09-2003

- Corrected a misinterpretation of the "The AES Cipher Algorithm in the
  SNMP's User-based Security Model" draft specification that lead to
  the incorrect encoding and decoding of the last block of the message.
- The syntax of the get_entries() method was changed to expect the column
  values to entered as full OBJECT IDENTIFIERs allowing the traversal of
  conceptual rows in different tables which are indexed identically.
- The processing of the serialization of an OBJECT IDENTIFIER was optimized.
- The oid_lex_sort() function was updated to order OBJECT IDENTIFIER strings
  padded with spaces as lexicographically greater than unpadded strings.
- An empty contextEngineId in a response message is now accepted during  
  the SNMPv3 discovery process.
- Corrected an argument validation error with the get_bulk_request()

RELEASE 4.1.0 MAY-06-2003

- Working in conjunction with the Extended Security Options Consortium
  (, support for additional privacy protocols 
  has been added to the SNMPv3 User-based Security Model.
  "Extension to the USM to Support Triple-DES EDE in 'Outside' CBC Mode"
  Reeder and Gudmunsson; October 1999, expired April 2000
  "The AES Cipher Algorithm in the SNMP's User-based Security Model"
  Blumenthal, Maino, and McCloghrie; October 2002, expired April 2003
- A new method called get_entries() was added to allow the retrieval
  of columns of a table entry using get-next-requests or get-bulk-requests.
- The argument "-maxrepetitions" was added to the get_table() method.
- Responses to SNMPv3 messages with non-default contextEngineIDs or
  contextNames are now properly processed.
- The method var_bind_names() was added to retrieve an array of the 
  ObjectNames in the VarBindList in the order in which they were 
  received in the GetResponse-PDU. 
RELEASE 4.0.3 SEP-09-2002

- Net::SNMP objects are now destroyed as expected when they are no
  longer referenced.  An internal reference to the object allocated by  
  the Net::SNMP::Dispatcher module is now properly cleared.
- A socket with a file descriptor value of 0 is now accepted by the 
  Net::SNMP module as a valid and open filehandle. 
- Removed an "optimization" which was intended to provide a smoother 
  initialization of the dispatcher but instead could lead to messages 
  incorrectly timing out. 

RELEASE 4.0.2 MAY-06-2002

- The SNMPv3 request message sent for time synchronization is now sent
  with the same securityLevel that is configured for the session.
- The "reserved" bits in the msgFlags field of an incoming SNMPv3
  message are now ignored as suggested by RFC 2572.
- When encrypting a SNMPv3 message, the padding byte(s) are now set to
  a value equal to the size of the padding.  "The actual pad value is
  irrelevant..." according RFC 2574 Section  However, there 
  are some agents that expect this byte pattern.
- Corrected a reference count mismatch which would leave a listening 
  socket open if no response is received from the remote agent.
- Corrected a "deep recursion" error that occurred when using the
  get_table() method to retrieve large tables in blocking mode.
- Using the "-delay" argument with the get_table() method no longer
  incorrectly delays between message exchanges when retrieving the table.
- Optimizations and improvements were made to the Net::SNMP::Dispatcher
  event scheduling and handling procedures.
- The "translate unsigned" logic now correctly handles properly 
  formatted (but unexpected) negative Counter64, Counter, Gauge, and 
  TimeTick values. 

RELEASE 4.0.1 JAN-01-2002

- SNMPv3 objects using authentication now send a separate authenticated
  request message for time synchronization while performing discovery.
- Non-blocking SNMPv1/2c messages with a "-delay" argument which are
  queued before entering the event loop are no longer incorrectly
- The Net::SNMP::Security::Community::security_model() method now 
  returns the correct value as reserved by RFC 2571.
- The first subidentifier in an OBJECT IDENTIFIER is now restricted to
  ccitt(0), iso(1), or joint-iso-ccitt(2) as specified by ISO/IEC 8825.
- Changed the appropriate CHECK blocks into BEGIN blocks to avoid the 
  "Can't call method 'send_pdu' on an undefined value" error when the 
  module is loaded using a quoted eval statement. 

RELEASE 4.0.0 NOV-09-2001

- The module has been completely redesigned to add support for SNMPv3 
  and to follow the SNMP Management Framework defined by RFC 2571.
- Perl version 5.6.0 or greater is now required to use the module.
- Updated the method calls to expect the same argument syntax regardless 
  of whether they are invoked by "blocking" or "non-blocking" objects. 
- The non-core modules Crypt::DES, Digest::MD5, Digest::SHA1, and 
  Digest::HMAC are now required to support SNMPv3.
- Added the ability to specify the local address and port number used by
  each object.

RELEASE 3.65 SEP-09-2001

- Corrected an error in the Net::SNMP::FSM module that would cause all
  response messages to be dropped in "non-blocking" mode if there is
  a recv() error.
- Updated the logic in the "blocking" response handling method such
  the transmit buffer is properly updated if there is a decode
  error while parsing the GetResponse-PDU. 
- Counter, Gauge, and TimeTick values that are incorrectly encoded as
  negative signed integers are now converted to unsigned values.  This
  feature can be disabled by setting the "-unsigned" flag to false 
  using the translate() method.
- An empty community name is now allowed.
- Updated the "non-blocking" example script.

RELEASE 3.60 SEP-09-2000

- Translation can now be enabled or disabled on a per ASN.1 type basis.
- The Net::SNMP::FSM "event loop" now prioritizes processing SNMP responses
  over other actions.
- A set of example scripts is now included with the distribution.

RELEASE 3.50 MAY-06-2000

- The methods that expect a SNMP GetResponse-PDU in "blocking" mode now ignore
  messages with request-ids that do not match the current request-id.  This
  change addresses a common occurrence of the "Received request-id xxxx is
  not equal to transmitted request-id xxxx" error.  The manifestation of this
  error that has been corrected occurs when a remote agent is too busy to
  respond immediately, buffers the request, and responds to the request after
  the Net::SNMP timeout has expired.
- A new argument "-delay" was added to all methods that can function in "non-
  blocking" mode.
- The Net::SNMP::FSM "event loop" sub-module was completely rewritten to more
  logically handle events.
- The get_table() method now uses get-bulk-requests instead of
  get-next-requests when the calling object's version is SNMPv2c.
- When a duplicate OBJECT IDENTIFIER is received in the VarBindList of a
  GetResponse-PDU, the duplicate is now padded with an appropriate number of
  spaces to make it an unique key in the HASH reference returned by the object.
- The default Maximum Transport Unit was changed from 484 to 1500.  The
  minimum allow MTU is now 484.

RELEASE 3.01 JAN-01-2000

- Performance enhancements were made to the most heavily used methods.
- Changed the default timeout to 5.0 seconds and the default number of retries
  to 1 to reduce network traffic and to work around a problem with responses 
  from certain routers when they are busy.  The total default timeout period
  remains the same at 10 seconds. 
- Removed the verify_ip() method and the "-verifyip" argument to the 

RELEASE 3.00 SEP-09-1999

- Added event loop based "non-blocking" support.
- Deprecated the verify_ip() method because verification of the received
  IP address and port number is no longer done.
- The "null" character (\000) no longer triggers an OCTET STRING in a
  GetResponse-PDU to be converted to a hexadecimal representation if
  translation is enabled.
- A single socket is now used for all Net::SNMP objects.
- Corrected an error where a blocking session would send one too many 
  retries and fail to listen for the last message sent.
- Added a new export tag ":snmp" used to define SNMP related symbols.
- New utility functions oid_context_match(), oid_lex_sort(), and 
  ticks_to_time() were added to provide support for commonly requested 
- The length of the varBind SEQUENCE is now properly encoded when multiple
  varBinds exist. 

RELEASE 2.00 MAY-06-1999

- Added support for SNMPv2c (Community-Based SNMPv2).
- Modified the ASN.1 encode routine for INTEGERs to correctly handle 
  positive values greater than 8388607.
- Added an installation test to verify basic usage of the module, 
  including verification of basic encode and decode methods.

RELEASE 1.40 APR-26-1999

- All parameters for the object that used to be only configurable via an 
  object method can now be modified at object creation by passing named
  arguments to the constructor.
- The translate() and debug() methods were modified to require a boolean
  argument to enable or disable the feature.  This deprecates the toggle
  functionality they had previously.
- New method verify_ip() added that enables or disables the verification
  of the IP address and UDP port number on datagrams received by the object.
- Added support for decoding ASN.1 lengths encoded with 3 or 4 bytes. 
- Installation tests for the modules required by Net::SNMP and for basic 
  socket functionality were added to the distribution. 

RELEASE 1.30 MAR-17-1999

- Modified the OBJECT INDENTIFIER decode method to return a leading dot
  on all identifiers if there was a leading dot on any OBJECT IDENTIFIER
  passed to the encode method. 
- Changed the address comparison used when receiving an UDP packet to just 
  include the port and address information in order to work around an AIX 

RELEASE 1.20 NOV-06-1998

- Now use gensym() from the Symbol module to generate typeglob references 
  for socket handles, correcting a memory leak.
- All private methods renamed to Perl programming style recommendations. 

RELEASE 1.10 OCT-14-1998

- New method trap() for sending SNMP Trap-PDUs added.
- New method error_status() which retrieves the SNMP error-status contained
  in the last SNMP GetResponse-PDU added.
- Named arguments for the method session() are now validated.
- New export tags ":asn1", ":generictrap", and ":ALL" added.
- New exportable symbols for generic-trap types added. 
- A comma contained in an OCTET STRING no longer causes the decoded result 
  of a GetResponse-PDU to be converted to a hexadecimal representation if 
  translation is enabled.
- The control characters \n\r\t no longer trigger an OCTET STRING in a
  GetResponse-PDU to be converted to a hexadecimal representation if 
  translation is enabled.
RELEASE 1.00 SEP-09-1998

- Initial release.


    $Id: Changes,v 6.1 2010/09/10 00:01:22 dtown Rel $