The Perl5 'SNMP' Extension Module
                      for the Net-SNMP Library
Contents
Introduction
Availability
Contact
Supported Platforms: Release Notes:
Installation
Operational Description: Trouble Shooting:
Acknowledgments
History
Copyright
Introduction

******************************NOTE NOTE NOTE**************************

     This module now relies on many other modules.  Ideally, do not try
     to build it independently, as it won't work as well.  Instead of
     running "perl Makefile.PL" in this directory, run it in the
     net-snmp/perl directory instead which has a global makefile used to
     build all the sub-modules in their proper order.

******************************NOTE NOTE NOTE**************************

Note: The perl SNMP 5.x module which comes with net-snmp 5.0 and higher is different than previous versions in a number of ways. Most importantly, it behaves like a proper net-snmp application and calls init_snmp properly, which means it will read configuration files and use those defaults where appropriate automatically parse MIB files, etc. This will likely affect your perl applications if you have, for instance, default values set up in your snmp.conf file (as the perl module will now make use of those defaults). The docmuentation, however, has sadly not been updated yet (aside from this note).

This is the Perl5 'SNMP' extension module. The SNMP module provides a full featured, tri-lingual SNMP (SNMPv3, SNMPv2c, SNMPv1) API. The SNMP module also provides an interface to the SMI MIB parse-tree for run-time access to parsed MIB data. The SNMP module internals rely on the Net-SNMP toolkit library (previously known as ucd-snmp). For information on the Net-SNMP library see the documentation provided with the Net-SNMP distribution or the project web page available on 'Source Forge':

http://www.net-snmp.org/

Availability

The most recent release of the Perl5 SNMP module can be found bundled with the latest Net-SNMP distibution available from:

http://www.net-snmp.org/download.html

(Note: The perl SNMP distribution obtained this way has the highest chance of being up to date and compatible with the Net-SNMP version with which it is bundled.)

A seperately bundled package of the SNMP module can be obtained from CPAN.

(Note: In previous releases this module was compatible with the CMU SNMP library. Starting with Perl5/SNMP-1.7 this module will only work with the Net-SNMP (aka ucd-snmp) library due to dependence on new features)

Contact

The following mailing list should be consider the primary support mechanism for this module:

net-snmp-users ATATAT lists.sourceforge.net mail list

(see http://www.net-snmp.org/lists/users/ to subscribe)

Supported Platforms:

Linux 1.2.x, 2.x
Solaris 2.x (see the net-snmp README.solaris file!) MS Windows
Many other UNIX variants
Let us know what it doesn't work on, as it should on most systems

Release Notes:

SNMP module version 5.x is being developed against NET-SNMP-5.0 see http://www.net-snmp.org/ for details.

Compatibility with earlier or later versions of Net-SNMP or UCD-SNMP is not guaranteed due to the dynamic nature of open software development :). The perl module will check the version of net-snmp you have installed for a match and warn you if they don't match exactly.

KNOWN BUGS:

The make test suite likely won't work perfectly. It relies on running an existing Net-SNMP SNMP agent and various configuration which makes it very hard to ensure exact compatibility. If "make test" fails on you we suggest you install the module anyway.

(none?) (HA!)


the rest of this file is likely out of date *********************** the rest of this file is likely out of date *********************** the rest of this file is likely out of date ***********************
Installation

Build and install the Net-SNMP package - see Net-SNMP README and INSTALL docs.

(Note: To ensure that any previous Net-SNMP, ucd-snmp or cmu snmp installation's library or headers are not used by mistake, use the -NET-SNMP-CONFIG directive to explicitly set the path to the net-snmp-config command that knows about the net-snmp installation you want to use.)

NOTE: build all the perl modules at once using the Makefile.PL in the net-snmp/perl directory rather than the one in this directory.

Unix

cd net-snmp/perl
perl Makefile.PL [-NET-SNMP-CONFIG="sh ../../net-snmp-config"] [-NET-SNMP-IN-SOURCE=true] make
make test
make install

FreeBSD

cd net-snmp/perl
perl Makefile.PL -NET-SNMP-CONFIG="sh ../../net-snmp-config" -NET-SNMP-IN-SOURCE=true make
make test
make install

Win32 (MSVC++)

This section covers installation of the Perl modules for Microsoft Visual C++ 6.0 and Microsoft Microsoft Development Environment 2003/2003 (MSVC 7.0/7.1). See the following sections for Cygwin and MinGW.

ActiveState Perl is required.

Note: With ActiveState Perl (currently at 5.8.2 build 808) and possibly other

         versions of Perl on Windows, if a Perl script modifies a
         system environment variable and then calls a C function, the
         C function will not see the new environment variable.  This
         problem can be seen with the failure of test #3 in the SNMP
         conf test (perl/SNMP/t/conf.t).  The change to the
         SNMPCONFPATH env variable is not seen by the calls to the C
         SNMP module.

Note: The source code should not be in a folder that contains a space. For

         example, compiling in your 'My Documents' or your Desktop (usually
         c:\Documents and Settings\xxxx\Desktop) is not supported.

Automatic building / testing with nmakeperl.bat:

  1. Ensure a static version of Net-SNMP has been compiled and installed. Also ensure the DLL version of snmplib has been compiled and installed. The Perl modules will not function correctly without a shared snmplib library or DLL.
  2. Install the regex win32 package (gnu_regex.exe). It is available from

    http://people.delphiforums.com/gjc/gnu_regex.html

    1. Copy regex.h to the include folder of MSVC++

      Example: "C:\Program Files\Microsoft Visual Studio .NET 2003\

      Vc7\include\regex.h"

    2. Copy gnu_regex.lib to the lib folder of MSVC++

      Example: "C:\Program Files\Microsoft Visual Studio .NET 2003\

      Vc7\lib\gnu_regex.lib"

    3. Copy gnu_regex.dll to your %windir%\system32 folder

      Example: "C:\winnt\system32\gnu_regex.dll"

  3. Set the environment PATH to locate "nmake", "cl", and "link".

    Visual Studio installs a VCVARS32.BAT batch file for this purpose.

  4. Using a command prompt window, cd to the source base directory.
  5. Invoke win32\nmakeperl.bat to build the Perl SNMP modules. If you see errors, review the "nmake.out" file first. If no errors there, then the modules built correctly, but the tests did not rigourously prove the mettle of the modules. Review "nmaketest.out". If the first three sections mostly pass, the modules are well formed.

    NOTE: If the tests fail, there may be a perl application left hanging.

    Use the Task Manager to remove any stale perl or snmp*.exe process.

  6. The final step is to invoke "nmake install". If no errors occurred, then the SNMP modules are available for use by your Perl programs.

Manual building / testing:

  1. Ensure a static version of Net-SNMP has been compiled and installed. Also ensure the DLL version of snmplib has been compiled and installed. The Perl modules will not function correctly without a shared snmplib library or DLL.
  2. Install the regex win32 package (gnu_regex.exe). It is available from

    http://people.delphiforums.com/gjc/gnu_regex.html

    1. Copy regex.h to the include folder of MSVC++

      Example: "C:\Program Files\Microsoft Visual Studio .NET 2003\

      Vc7\include\regex.h"

    2. Copy gnu_regex.lib to the lib folder of MSVC++

      Example: "C:\Program Files\Microsoft Visual Studio .NET 2003\

      Vc7\lib\gnu_regex.lib"

    3. Copy gnu_regex.dll to your %windir%\system32 folder

      Example: "C:\winnt\system32\gnu_regex.dll"

  3. Set the environment PATH to locate "nmake", "cl", and "link".

    Visual Studio installs a VCVARS32.BAT for this purpose.

  4. Using a command prompt window, cd to the perl directory.
  5. Type:

perl Makefile.PL CAPI=TRUE -NET-SNMP-IN-SOURCE=TRUE

to compile against the RELEASE version of Net-SNMP, or:

perl Makefile.PL CAPI=TRUE -NET-SNMP-IN-SOURCE=TRUE -NET-SNMP-DEBUG=TRUE

to compile against the DEBUG version of Net-SNMP.

         nmake
         nmake test
         nmake install

         Note: The --NET-SNMP-IN-SOURCE=TRUE causes the Makefile to use the 
               library files from the installed Net-SNMP directory.
               To specify the installed Net-SNMP directory, use:

               perl Makefile.PL CAPI=TRUE -NET-SNMP-PATH="c:\usr"

               Note: -NET-SNMP-DEBUG has no effect while compiling against an 
                     installed copy of Net-SNMP.

         Note: To include OpenSSL, see the net-snmp/README.win32 to compile 
               libsnmp with libeay32 and see that libeay.lib is in the
               lib folder, or in the lib folder of the installed
               Net-SNMP if using -NET-SNMP-PATH.  For example,
               c:\usr\lib

Note: 'nmake test' will automatically start and stop the

          agent(snmpd) and trap receiver (snmptrapd) while testing the
          SNMP module.

Win32 (Cygwin):

cd net-snmp\perl
perl Makefile.PL -NET-SNMP-IN-SOURCE=true make
make test
make install

If you get an error saying your system can't compile, you are probably missing the regex library. Install regex from http://mirrors.sunsite.dk/cygwin/release/regex/regex-4.4-2-src.tar.bz2

Note: The source code should not be in a folder that contains a space. For

         example, compiling in your 'My Documents' or your Desktop (usually
         c:\Documents and Settings\xxxx\Desktop) is not supported.

Win32 (MinGW):

Note: As of February 25th, 2004, the MinGW build of Net-SNMP does not

          compile the DLL version of libsnmp.  Some modules will not function
          correctly without a shared library / DLL.  The OID module does not
          appear to work at all without the DLL, and some parts of other 
          modules may not work.  For example, sharing configurations between
          modules which is why the SNMP conf test fails.

Note: The source code should not be in a folder that contains a space. For

         example, compiling in your 'My Documents' or your Desktop (usually
         c:\Documents and Settings\xxxx\Desktop) is not supported.

These directions are for MinGW 3.1.0 with MSYS 1.0.9 and ActiveState Perl. Compiling the Perl modules using a MinGW built Perl environment has not been tested.

Note: With ActiveState Perl (currently at 5.8.2 build 808) and

         possibly other versions of Perl on Windows, if a Perl script
         modifies a system environment variable and then calls a C
         function, the C function will not see the new environment
         variable.  This problem can be seen with the failure of test
         #3 in the SNMP conf test (perl/SNMP/t/conf.t).  The change to
         the SNMPCONFPATH env variable is not seen by the calls to the
         C SNMP module.

The main Net-SNMP package must be compiled with the regex library. See Net-SNMP README.win32 for compiling with MinGW.

The following additional software is required:

dmake
http://www.cpan.org/authors/id/GSAR/dmake-4.1pl1-win32.zip

ExtUtils-FakeConfig:
http://search.cpan.org/~mbarbon/ExtUtils-FakeConfig-0.05/

Note: A PPM package is available from ActiveState for

          ExtUtils-FakeConfig, but it does not include the
          make_implib.pl script.  Downloading from CPAN is
          recommended.

Installing DMAKE and ExtUtils-FakeConfig:

  1. Install DMAKE as described in the README.NOW contained in the DMAKE .ZIP file ensuring the DMAKE program can be found in the system path.
  2. Extract ExtUtils-FakeConfig-0.05.zip to a temporary folder.
  3. Add the MinGW bin folder to your system path.
  4. Open a Windows command prompt (cmd) and cd into ExtUtils-FakeConfig-0.05 and typet he following to build and install the ExtUtils-FakeConfig module:

    perl Makefile.PL dmake dmake install

  5. A Perl import library needs to be created using the ExtUtils-FakeConfig make_implib.pl script.

    For ActiveState Perl 5.6.x installed to c:\Perl, type the following on one line:

         perl script/make_implib.pl --output-dir=C:/Perl/lib/CORE 
           --output-lib=libperl56.a --target=mingw c:/Perl/bin/Perl56.dll

       For ActiveState Perl 5.8.x installed to c:\Perl, type the
       following on one line:

         perl script/make_implib.pl --output-dir=C:/Perl/lib/CORE 
           --output-lib=libperl58.a --target=mingw c:/Perl/bin/Perl58.dll

Building the Perl module:

  1. Complete the section titled 'Installing DMAKE and ExtUtils-FakeConfig'
  2. Open an MSYS shell and cd into the net-snmp/Perl folder and type the following on one line:

perl -MConfig_m Makefile.PL -NET-SNMP-IN-SOURCE=true DEFINE=-DMINGW_PERL

3. Open a Windows command prompt (cmd) and cd into the net-snmp/perl folder

and type:

         dmake
         dmake test
         dmake install

       Note:  'dmake test' will automatically start and stop the agent(snmpd) and 
              trap receiver (snmptrapd) while testing the SNMP module.  

4. Remove the MinGW bin folder to your system path if it was not already in

your path for step 3 of 'Installing DMAKE and ExtUtils-FakeConfig'.

Operational Description:

The basic operations of the SNMP protocol are provided by this module through an object oriented interface for modularity and ease of use. The primary class is SNMP::Session which encapsulates the persistent aspects of a connection between the management application and the managed agent. Internally the class is implemented as a blessed hash reference. This class supplies 'get', 'getnext', 'set', 'fget', and 'fgetnext' and other method calls. The methods take a variety of input argument formats and support both synchronous and asynchronous operation through a polymorphic API (i.e., method behaviour varies dependent on args passed - see below).

A description of the fields which can be specified when an SNMP::Session object is created follows:

SNMP::Session

public
DestHost - default 'localhost', hostname or ip addr of SNMP agent Community - default 'public', SNMP community string (used for both R/W) Version - default '1', [2 (same as 2c), 2c, 3] RemotePort - default '161', allow remote UDP port to be overridden Timeout - default '1000000', micro-seconds before retry Retries - default '5', retries before failure RetryNoSuch - default '0', if enabled NOSUCH errors in 'get' pdus will

be repaired, removing the varbind in error, and resent - undef will be returned for all NOSUCH varbinds, when set to '0' this feature is disabled and the entire get request will fail on any NOSUCH error (applies to v1 only) SecName - default 'initial', security name (v3) SecLevel - default 'noAuthNoPriv', security level [noAuthNoPriv,

authNoPriv, authPriv] (v3) SecEngineId - default <none>, security engineID, will be probed if not

supplied (v3) ContextEngineId - default <SecEngineId>, context engineID, will be

probed if not supplied (v3) Context - default '', context name (v3) AuthProto - default 'MD5', authentication protocol [MD5, SHA] (v3) AuthPass - default <none>, authentication passphrase PrivProto - default 'DES', privacy protocol [DES] (v3) PrivPass - default <none>, privacy passphrase (v3) VarFormats - default 'undef', used by 'fget[next]', holds an hash

reference of output value formatters, (e.g., {<obj> => <sub-ref>, ... }, <obj> must match the <obj> and format used in the get operation. A special <obj>, '*', may be used to apply all <obj>s, the supplied sub is called to translate the value to a new format. The sub is called passing the Varbind as the arg TypeFormats - default 'undef', used by 'fget[next]', holds an hash

reference of output value formatters, (e.g., {<type> => <sub-ref>, ... }, the supplied sub is called to translate the value to a new format, unless a VarFormat mathces first (e.g., $session->{TypeFormats}{INTEGER} = \&mapEnum(); although this can be done more efficiently by enabling $SNMP::use_enums or session creation param 'UseEnums') UseLongNames - defaults to the value of SNMP::use_long_names at time

of session creation. set to non-zero to have <tags> for 'getnext' methods generated preferring longer Mib name convention (e.g., system.sysDescr vs just sysDescr) UseSprintValue - defaults to the value of SNMP::use_sprint_value at time

of session creation. set to non-zero to have return values for 'get' and 'getnext' methods formatted with the libraries sprint_value function. This will result in certain data types being returned in non-canonical format Note: values returned with this option set may not be appropriate for 'set' operations (see discussion of value formats in <vars> description section) UseEnums - defaults to the value of SNMP::use_enums at time of session

creation. set to non-zero to have integer return values converted to enumeration identifiers if possible, these values will also be acceptable when supplied to 'set' operations UseNumeric - defaults to the value of SNMP::use_numeric at time of session

creation. set to non-zero to have <tags> returned by the 'get' methods untranslated (i.e. dotted-decimal). Setting the UseLongNames value for the session is highly recommended. BestGuess - defaults to the value of SNMP::best_guess at time of session

creation. this setting controls how <tags> are parsed. setting to 0 causes a regular lookup. setting to 1 causes a regular expression match (defined as -Ib in snmpcmd) and setting to 2 causes a random access lookup (defined as -IR in snmpcmd). ErrorStr - read-only, holds the error message assoc. w/ last request ErrorNum - read-only, holds the snmp_err or status of last request ErrorInd - read-only, holds the snmp_err_index when appropriate

private
DestAddr - internal field used to hold the translated DestHost field SessPtr - internal field used to cache a created session structure
methods
new(<fields>) - Constructs a new SNMP::Session object. The fields are

passed to the constructor as a hash list (e.g., $session = new SNMP::Session(DestHost => 'foo', Community => 'private');), returns an object reference or undef in case of error. update(<fields>)- Updates the SNMP::Session object with the values fields

passed in as a hash list (similar to new(<fields>)) (WARNING! not fully implemented) get(<vars>[,<callback>])

SNMP::TrapSession - supports all applicable fields from SNMP::Session

(see above)

methods
new(<fields>) - Constructs a new SNMP::TrapSession object. The fields are

passed to the constructor as a hash list (e.g., $trapsess = new SNMP::Session(DestHost => 'foo', Community => 'private');), returns an object reference or undef in case of error. trap(enterprise, agent, generic, specific, uptime, <vars>)

$sess->trap(enterprise=>'.1.3.6.1.4.1.2021', # or 'ucdavis' [default]

agent => '127.0.0.1', # or 'localhost',[dflt 1st intf on host] generic => specific, # can be omitted if 'specific' supplied specific => 5, # can be omitted if 'generic' supplied uptime => 1234, # dflt to localhost uptime (0 on win32) [[ifIndex, 1, 1],[sysLocation, 0, "here"]]); # optional vars

# always last or v2 format trap(oid, uptime, <vars>)

$sess->trap(oid => 'snmpRisingAlarm',

uptime => 1234, [[ifIndex, 1, 1],[sysLocation, 0, "here"]]); # optional vars

# always last

Acceptable variable formats:
<vars> may be one of the following forms:

SNMP::VarList: - represents an array of MIB objects to get or set,

                      implemented as a blessed reference to an array of
                      SNMP::Varbinds, (e.g., [<varbind1>, <varbind2>, ...])

SNMP::Varbind: - represents a single MIB object to get or set, implemented as

                      a blessed reference to a 4 element array;
                      [<obj>, <iid>, <val>, <type>].
                      <obj>  - one of the following forms:
                             1) leaf identifier (e.g., 'sysDescr') assumed to be
                                unique for practical purposes
                             2) fully qualified identifier (e.g.,
                             '.iso.org.dod.internet.mgmt.mib-2.system.sysDescr')
                             3) fully qualified, dotted-decimal, numeric OID (e.g.,
                                '.1.3.6.1.2.1.1.1')
                      <iid>  - the dotted-decimal, instance identifier. for
                               scalar MIB objects use '0'
                   <val>  - the SNMP data value retrieved from or being set
                               to the agents MIB. for (f)get(next) operations
                               <val> may have a variety of formats as determined by
                               session and package settings. However for set
                               operations the <val> format must be canonical to
                               ensure unambiguous translation. The canonical forms
                               are as follows:
                            OBJECTID => dotted-decimal (e.g., .1.3.6.1.2.1.1.1)
                            OCTETSTR => perl scalar containing octets,
                            INTEGER => decimal signed integer (or enum),
                            NETADDR => dotted-decimal,
                            IPADDR => dotted-decimal,
                            COUNTER => decimal unsigned integer,
                            COUNTER64  => decimal unsigned integer,
                            GAUGE,  => decimal unsigned integer,
                            UINTEGER,  => decimal unsigned integer,
                               TICKS,  => decimal unsigned integer,
                               OPAQUE => perl scalar containing octets,
                                    NULL,  => perl scalar containing nothing,

                      <type> - SNMP data type (see list above), this field is
                               populated by 'get' and 'getnext' operations. In
                               some cases the programmer needs to populate this
                               field when passing to a 'set' operation. this
                               field need not be supplied when the attribute
                               indicated by <tag> is already described by loaded
                               Mib modules. for 'set's, if a numeric OID is used
                               and the object is not currently in the loaded Mib,
                               the <type> field must be supplied

simple string - light weight form of <var> used to 'set' or 'get' a

                      single attribute without constructing an SNMP::Varbind.
                      stored in a perl scalar, has the form '<tag>.<iid>',
                      (e.g., 'sysDescr.0'). for 'set' operations the value
                      is passed as a second arg. Note: This argument form is
                      not updated in get[next] operations as are the other forms.

Acceptable callback formats:
<callback> may be one of the following forms:

without arguments:

       \&subname
       sub { ... }
    or with arguments:
       [ \&subname, $arg1, ... ]
       [ sub { ... }, $arg1, ... ]
       [ "method", $obj, $arg1, ... ]

callback will be called when response is received or timeout occurs. the last argument passed to callback will be a SNMP::VarList reference. In case of timeout the last argument will be undef.

SNMP package variables and functions:

$SNMP::VERSION - the current version specifier (e.g., 3.1.0)

$SNMP::auto_init_mib - default '1', set to 0 to disable automatic reading

                           of the MIB upon session creation. set to non-zero
                           to call initMib at session creation which will result
                           in MIB loading according to Net-SNMP env. variables
                        (see man mib_api)

    $SNMP::verbose       - default '0', controls warning/info output of
                           SNMP module, 0 => no output, 1 => enables warning/info
                           output from SNMP module itself (is also controlled
                           by SNMP::debugging - see below)

$SNMP::use_long_names - default '0', set to non-zero to enable the use of

                           longer Mib identifiers. see translateObj. will also
                           influence the formatting of <tag> in varbinds returned
                           from 'getnext' operations. Can be set on a per session
                           basis (UseLongNames)

$SNMP::use_sprint_value - default '0', set to non-zero to enable formatting of

                           response values using the snmp libraries sprint_value
                           function. can also be set on a per session basis (see
                           UseSprintValue) Note: returned values may not be
                           suitable for 'set' operations

    $SNMP::use_enums     - default '0',set non-zero to return values as enums and
                           allow sets using enums where appropriate. integer data
                           will still be accepted for set operations. can also be
                           set on a per session basis (see UseEnums)

$SNMP::use_numeric - default '0', set to non-zero to return tags as numeric

                           OID's, instead of translating them.  Also setting
                           $SNMP::use_long_names to non-zero is highly recommended.

$SNMP::best_guess - default '0'. this setting controls how <tags> are

                           parsed.  setting to 0 causes a regular lookup.  setting 
                           to 1 causes a regular expression match (defined as -Ib 
                           in snmpcmd) and setting to 2 causes a random access 
                           lookup (defined as -IR in snmpcmd).  can also be set 
                           on a per session basis (see BestGuess)

$SNMP::save_descriptions - default '0',set non-zero to have mib parser save

                           attribute descriptions. must be set prior to mib
                           initialization

    $SNMP::debugging     - default '0', controls debugging output level
                           within SNMP module and libsnmp
                           1 => enables 'SNMP::verbose' (see above)
                           2 => level 1 plus snmp_set_do_debugging(1),
                           3 => level 2 plus snmp_set_dump_packet(1)

$SNMP::dump_packet - default '0', set [non-]zero to independently set

snmp_set_dump_packet()

    %SNMP::MIB           - a tied hash to access parsed MIB information. After
                           the MIB has been loaded this hash allows access to
                           to the parsed in MIB meta-data(the structure of the
                           MIB (i.e., schema)). The hash returns blessed
                           references to SNMP::MIB::NODE objects which represent
                           a single MIB attribute. The nodes can be fetched with
                           multiple 'key' formats - the leaf name (e.g.,sysDescr)
                           or fully/partially qualified name (e.g.,
                           system.sysDescr) or fully qualified numeric OID. The
                           returned node object supports the following fields:

           objectID      - dotted decimal fully qualified OID
           label         - leaf textual identifier (e.g., 'sysDescr')
           subID         - leaf numeric OID component of objectID (e.g., '1')
           moduleID      - textual identifier for module (e.g., 'RFC1213-MIB')
           parent        - parent node
           children      - array reference of children nodes
           nextNode      - next lexico node (BUG!does not return in lexico order)
           type          - returns application type (see getType for values)
           access        - returns ACCESS (ReadOnly, ReadWrite, WriteOnly,
                           NoAccess, Notify, Create)
           status        - returns STATUS (Mandatory, Optional, Obsolete,
                           Deprecated, Current)
           syntax        - returns 'textualConvention' if defined else 'type'
           textualConvention - returns TEXTUAL-CONVENTION
           units         - returns UNITS
           hint          - returns HINT
           enums         - returns hash ref {tag => num, ...}
           ranges        - returns array ref of hash ref [{low=>num, high=>num}]
           defaultValue  - returns default value
           description   - returns DESCRIPTION ($SNMP::save_descriptions must
                           be set prior to MIB initialization/parsing)

&SNMP::setMib(<file>) - allows dynamic parsing of the mib and explicit

                            specification of mib file independent of environment
                            variables. called with no args acts like initMib,
                            loading MIBs indicated by environment variables (see
                            Net-SNMP mib_api docs). passing non-zero second arg
                            forces previous mib to be freed and replaced
                            (Note: second arg not working since freeing previous
                             Mib is more involved than before).

    &SNMP::initMib()     - calls library netsnmp_init_mib function if MIB not 
                           already loaded - does nothing if MIB already loaded.
                           Will parse directories and load modules according to
                           environment variables described in Net-SNMP
                           documentations.
                           (see man mib_api, MIBDIRS, MIBS, MIBFILE(S), etc.)

&SNMP::addMibDirs(<dir>,...) - calls library add_mibdir for each directory

                           supplied. will cause directory(s) to be added to
                           internal list and made available for searching in
                           subsequent loadModules calls

&SNMP::addMibFiles(<file>,...) - calls library read_mib function. The file(s)

                          supplied will be read and all Mib module definitions
                          contained therein will be added to internal mib tree
                          structure

&SNMP::loadModules(<mod>,...) - calls library read_module function. The

                          module(s) supplied will be searched for in the
                          current mibdirs and and added to internal mib tree
                          structure. Passing special <mod>, 'ALL', will cause
                          all known modules to be loaded.

&SNMP::unloadModules(<mod>,...) - Not Implemented

&SNMP::translateObj(<var>[,arg,[arg]]) - will convert a text obj tag to an

                          OID and vice-versa. Any iid suffix is retained 
                          numerically.  Default behaviour when converting a 
                          numeric OID to text form is to return leaf identifier 
                          only (e.g.,'sysDescr') but when $SNMP::use_long_names 
                          is non-zero or a non-zero second arg is supplied it 
                          will return a longer textual identifier.  An optional 
                          third argument of non-zero will cause the module name 
                          to be prepended to the text name (e.g. 
                          'SNMPv2-MIB::sysDescr').  When converting a text obj, 
                          the $SNMP::best_guess option is used.  If no Mib is 
                          loaded when called and $SNMP::auto_init_mib is enabled 
                          then the Mib will be loaded. Will return 'undef' upon 
                          failure.

&SNMP::getType(<var>) - return SNMP data type for given textual identifier

                           OBJECTID, OCTETSTR, INTEGER, NETADDR, IPADDR, COUNTER
                           GAUGE, TIMETICKS, OPAQUE, or undef

&SNMP::mapEnum(<var>) - converts integer value to enumeration tag defined

                            in Mib or converts tag to integer depending on
                            input. the function will return the corresponding
                            integer value or tag for a given MIB attribute
                            and value. The function will sense which direction
                            to perform the conversion. Various arg formats are
                            supported
                            $val = SNMP::mapEnum($varbind);
                            # where $varbind is SNMP::Varbind or equiv
                            # note: $varbind will be updated
                            $val = SNMP::mapEnum('ipForwarding', 'forwarding');
                            $val = SNMP::mapEnum('ipForwarding', 1);

&SNMP::MainLoop([<timeout>, [<callback>]])

&SNMP::finish()

Exported SNMP utility functions
&snmp_get() - takes args of SNMP::Session::new followed by those of

SNMP::Session::get

&snmp_getnext() - takes args of SNMP::Session::new followed by those of

SNMP::Session::getnext

&snmp_set() - takes args of SNMP::Session::new followed by those of

SNMP::Session::set

&snmp_trap() - takes args of SNMP::TrapSession::new followed by those of

SNMP::TrapSession::trap

Note: utility functions do not support async operation yet.

Trouble Shooting:

If problems occur there are number areas to look at to narrow down the possibilities.

The first step should be to test the Net-SNMP installation independently from the Perl5 SNMP interface.

Try running the apps from the Net-SNMP distribution.

Make sure your agent (snmpd) is running and properly configured with read-write access for the community you are using.

Ensure that your MIBs are installed and environment variables are set appropriately (see man mib_api)

Be sure to ensure headers and libraries from old CMU installations are not being used by mistake (see -NET-SNMP-PATH).

If the problem occurs during compilation/linking check that the snmp library being linked is actually the Net-SNMP library (there have been name conflicts with existing snmp libs).

Also check that the header files are correct and up to date.

Sometimes compiling the Net-SNMP library with 'position-independent-code' enabled is required (HPUX specifically).

If you cannot resolve the problem you can post to comp.lang.perl.modules or email net-snmp-users@lists.sourceforge.net.

please give sufficient information to analyze the problem (OS type, versions for OS/Perl/net-SNMP/compiler, complete error output, etc.)

Acknowledgments

Many thanks to all those who supplied patches, suggestions and feedback.

Joe Marzot (the original author)
Wes Hardaker and the net-snmp-coders Dave Perkins
Marcel Wiget
David Blackburn
John Stofell
Gary Hayward
Claire Harrison
Achim Bohnet
Doug Kingston
Jacques Vidrine
Carl Jacobsen
Wayne Marquette
Scott Schumate
Michael Slifcak
Srivathsan Srinivasagopalan
Bill Fenner
Jef Peeraer
Daniel Hagerty
Karl "Rat" Schilke and Electric Lightwave, Inc. Perl5 Porters
Alex Burger

Apologies to any/all who's patch/feature/request was not mentioned or included - most likely it was lost when paying work intruded on my fun. Please try again if you do not see a desired feature. This may actually turn out to be a decent package with such excellent help and the fact that I have more time to work on it than in the past.

Copyright

[See the COPYING file for the copyright license of Net-SNMP]

     Copyright (c) 1995-2000 G. S. Marzot. All rights reserved.
     This program is free software; you can redistribute it and/or
     modify it under the same terms as Perl itself.

     Copyright (c) 2001-2002 Networks Associates Technology, Inc.  All
     Rights Reserved.  This program is free software; you can
     redistribute it and/or modify it under the same terms as Perl
     itself.

     Copyright (c) 2003-2006 SPARTA, Inc.  All Rights Reserved.  This
     program is free software; you can redistribute it and/or modify
     it under the same terms as Perl itself.