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SNMP(3) 	       User Contributed Perl Documentation		 SNMP(3)

NAME
     SNMP - The Perl5 'SNMP' Extension Module for the Net-SNMP SNMP package.

SYNOPSIS
      use SNMP;
      ...
      $sess = new SNMP::Session(DestHost => localhost, Community => public);
      $val = $sess->get('sysDescr.0');
      ...
      $vars = new SNMP::VarList([sysDescr,0], [sysContact,0], [sysLocation,0]);
      @vals = $sess->get($vars);
      ...
      $vb = new SNMP::Varbind();
      do {
	 $val = $sess->getnext($vb);
	 print "@{$vb}\n";
      } until ($sess->{ErrorNum});
      ...
      $SNMP::save_descriptions = 1;
      SNMP::initMib(); # assuming mib is not already loaded
      print "$SNMP::MIB{sysDescr}{description}\n";

DESCRIPTION
     Note: The perl SNMP 5.0 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 de-
     faults).  The documentation, however, has sadly not been updated yet (aside
     from this note), nor is the read_config default usage implementation fully
     complete.

     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. In-
     ternally the class is implemented as a blessed hash reference. This class
     supplies 'get', 'getnext', 'set', 'fget', and 'fgetnext' method calls. The
     methods take a variety of input argument formats and support both synchro-
     nous and asynchronous operation through a polymorphic API (i.e., method be-
     haviour varies dependent on args passed - see below).

SNMP::Session
     $sess = new SNMP::Session(DestHost => 'host', ...)

     The following arguments may be passed to new as a hash.

   Basic Options
     DestHost
	 Hostname or IP address of the SNMP agent you want to talk to.	Speci-
	 fied in Net-SNMP formatted agent addresses.  These addresses typically
	 look like one of the following:

	   localhost
	   tcp:localhost
	   tls:localhost
	   tls:localhost:9876
	   udp6:[::1]:9876
	   unix:/some/path/to/file/socket

	 Defaults to 'localhost'.

     Version
	 SNMP version to use.

	 The default is taken from library configuration - probably 3 [1, 2
	 (same as 2c), 2c, 3].

     Timeout
	 The number of micro-seconds to wait before resending a request.

	 The default is '1000000'

     Retries
	 The number of times to retry a request.

	 The default is '5'

     RetryNoSuch
	 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)

	 The default is '0'.

   SNMPv3/TLS Options
     OurIdentity
	 Our X.509 identity to use, which should either be a fingerprint or the
	 filename that holds the certificate.

     TheirIdentity
	 The remote server's identity to connect to, specified as either a fin-
	 gerprint or a file name.  Either this must be specified, or the host-
	 name below along with a trust anchor.

     TheirHostname
	 The remote server's hostname that is expected.  If their certificate
	 was signed by a CA then their hostname presented in the certificate
	 must match this value or the connection fails to be established (to
	 avoid man-in-the-middle attacks).

     TrustCert
	 A trusted certificate to use as trust anchor (like a CA certificate)
	 for verifying a remote server's certificate.  If a CA certificate is
	 used to validate a certificate then the TheirHostname parameter must
	 also be specified to ensure their presented hostname in the certificate
	 matches.

   SNMPv3/USM Options
     SecName
	 The SNMPv3 security name to use (most for SNMPv3 with USM).

	 The default is 'initial'.

     SecLevel
	 The SNMPv3 security level to use [noAuthNoPriv, authNoPriv, authPriv]
	 (v3)

	 The default is 'noAuthNoPriv'.

     SecEngineId
	 The SNMPv3 security engineID to use (if the snmpv3 security model needs
	 it; for example USM). The format is as a string without the leading
	 '0x'.	So if snmptrapd.conf has "-e 0x8000000001020304", use Se-
	 cEngineId => '8000000001020304'.

	 The default is <none>, security engineID and it will be probed if not
	 supplied (v3)

     ContextEngineId
	 The SNMPv3 context engineID to use.

	 The default is the <none> and will be set either to the SecEngineId
	 value if set or discovered or will be discovered in other ways if using
	 TLS (RFC5343 based discovery).

     Context
	 The SNMPv3 context name to use.

	 The default is '' (an empty string)

     AuthProto
	 The SNMPv3/USM authentication protocol to use [MD5, SHA].

	 The default is 'MD5'.

     AuthPass
	 The SNMPv3/USM authentication passphrase to use.

	 default <none>, authentication passphrase

     PrivProto
	 The SNMPv3/USM privacy protocol to use [DES, AES].

	 The default is 'DES'.

     PrivPass
	 The SNMPv3/USM privacy passphrase to use.

	 default <none>, privacy passphrase (v3)

     AuthMasterKey
     PrivMasterKey
     AuthLocalizedKey
     PrivLocalizedKey
	 Directly specified SNMPv3 USM user keys (used if you want to specify
	 the keys instead of deriving them from a password as above).

   SNMPv1 and SNMPv2c Options
     Community
	 For SNMPv1 and SNMPv2c, the clear-text community name to use.

	 The default is 'public'.

   Other Configuration Options
     VarFormats
	 default 'undef', used by 'fget[next]', holds an hash reference of out-
	 put 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 out-
	 put value formatters, (e.g., {<type> => <sub-ref>, ... }, the supplied
	 sub is called to translate the value to a new format, unless a VarFor-
	 mat mathces first (e.g., $sess->{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 cre-
	 ation. 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 cre-
	 ation. set to non-zero to have return values for 'get' and 'getnext'
	 methods formatted with the libraries snprint_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 sup-
	 plied to 'set' operations

     UseNumeric
	 defaults to the value of SNMP::use_numeric at time of session creation.
	 set to non-zero to have <tags> for get methods returned as numeric
	 OID's rather than descriptions.  UseLongNames will be set so that the
	 full OID is returned to the caller.

     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 (de-
	 fined as -Ib in snmpcmd) and setting to 2 causes a random access lookup
	 (defined as -IR in snmpcmd).

     NonIncreasing
	 defaults to the value of SNMP::non_increasing at time of session cre-
	 ation. this setting controls if a non-increasing OID during bulkwalk
	 will causes an error. setting to 0 causes the default behaviour (which
	 may, in very badly performing agents, result in a never-ending loop).
	 setting to 1 causes an error (OID not increasing) when this error oc-
	 cur.

     ErrorStr
	 read-only, holds the error message assoc. w/ last request

     ErrorNum
	 read-only, holds the snmp_err or staus of last request

     ErrorInd
	 read-only, holds the snmp_err_index when appropriate

     Private variables:

     DestAddr
	 internal field used to hold the translated DestHost field

     SessPtr
	 internal field used to cache a created session structure

     RemotePort
	 Obsolete.  Please use the DestHost specifier to indicate the hostname
	 and port combination instead of this paramet.

   SNMP::Session methods
     $sess->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)

     $sess->get(<vars> [,<callback>])
	 do SNMP GET, multiple <vars> formats accepted.  for syncronous opera-
	 tion <vars> will be updated with value(s) and type(s) and will also re-
	 turn retrieved value(s). If <callback> supplied method will operate
	 asynchronously

     $sess->fget(<vars> [,<callback>])
	 do SNMP GET like 'get' and format the values according the handlers
	 specified in $sess->{VarFormats} and $sess->{TypeFormats}

     $sess->getnext(<vars> [,<callback>])
	 do SNMP GETNEXT, multiple <vars> formats accepted, returns retrieved
	 value(s), <vars> passed as arguments are updated to indicate next lexi-
	 cographical <obj>,<iid>,<val>, and <type>

	 Note: simple string <vars>,(e.g., 'sysDescr.0') form is not updated. If
	 <callback> supplied method will operate asynchronously

     $sess->fgetnext(<vars> [,<callback>])
	 do SNMP GETNEXT like getnext and format the values according the han-
	 dlers specified in $sess->{VarFormats} and $sess->{TypeFormats}

     $sess->set(<vars> [,<callback>])
	 do SNMP SET, multiple <vars> formats accepted.  the value field in all
	 <vars> formats must be in a canonical format (i.e., well known format)
	 to ensure unambiguous translation to SNMP MIB data value (see discus-
	 sion of canonical value format <vars> description section), returns
	 snmp_errno. If <callback> supplied method will operate asynchronously

     $sess->getbulk(<non-repeaters>, <max-repeaters>, <vars>)
	 do an SNMP GETBULK, from the list of Varbinds, the single next lexico
	 instance is fetched for the first n Varbinds as defined by <non-re-
	 peaters>. For remaining Varbinds, the m lexico instances are retrieved
	 each of the remaining Varbinds, where m is <max-repeaters>.

     $sess->bulkwalk(<non-repeaters>, <max-repeaters>, <vars> [,<callback>])
	 Do a "bulkwalk" of the list of Varbinds.  This is done by sending a
	 GETBULK request (see getbulk() above) for the Varbinds.  For each re-
	 quested variable, the response is examined to see if the next lexico
	 instance has left the requested sub-tree.  Any further instances re-
	 turned for this variable are ignored, and the walk for that sub-tree is
	 considered complete.

	 If any sub-trees were not completed when the end of the responses is
	 reached, another request is composed, consisting of the remaining vari-
	 ables.  This process is repeated until all sub-trees have been com-
	 pleted, or too many packets have been exchanged (to avoid loops).

	 The bulkwalk() method returns an array containing an array of Varbinds,
	 one for each requested variable, in the order of the variable requests.
	 Upon error, bulkwalk() returns undef and sets $sess->ErrorStr and
	 $sess->ErrorNum.  If a callback is supplied, bulkwalk() returns the
	 SNMP request id, and returns immediately.  The callback will be called
	 with the supplied argument list and the returned variables list.

	 Note: Because the client must "discover" that the tree is complete by
	 comparing the returned variables with those that were requested, there
	 is a potential "gotcha" when using the max-repeaters value.  Consider
	 the following code to print a list of interfaces and byte counts:

	     $numInts = $sess->get('ifNumber.0');
	     ($desc, $in, $out) = $sess->bulkwalk(0, $numInts,
			   [['ifDescr'], ['ifInOctets'], ['ifOutOctets']]);

	     for $i (0..($numInts - 1)) {
		 printf "Interface %4s: %s inOctets, %s outOctets\n",
			   $$desc[$i]->val, $$in[$i]->val, $$out[$i]->val;
	     }

	 This code will produce *two* requests to the agent -- the first to get
	 the interface values, and the second to discover that all the informa-
	 tion was in the first packet.	To get around this, use '$numInts + 1'
	 for the max_repeaters value.  This asks the agent to include one addi-
	 tional (unrelated) variable that signals the end of the sub-tree, al-
	 lowing bulkwalk() to determine that the request is complete.

     $results = $sess->gettable(<TABLE OID>, <OPTIONS>)
	 This will retrieve an entire table of data and return a hash reference
	 to that data.	The returned hash reference will have indexes of the OID
	 suffixes for the index data as the key.  The value for each entry will
	 be another hash containing the data for a given row.  The keys to that
	 hash will be the column names, and the values will be the data.

	 Example:

	   #!/usr/bin/perl

	   use SNMP;
	   use Data::Dumper;

	   my $s = new SNMP::Session(DestHost => 'localhost');

	   print Dumper($s->gettable('ifTable'));

	 On my machine produces:

	   $VAR1 = {
		     '6' => {
			      'ifMtu' => '1500',
			      'ifPhysAddress' => 'PV',
			      # ...
			      'ifInUnknownProtos' => '0'
			    },
		     '4' => {
			      'ifMtu' => '1480',
			      'ifPhysAddress' => '',
			      # ...
			      'ifInUnknownProtos' => '0'
			    },
		     # ...
		    };

	 By default, it will try to do as optimized retrieval as possible.
	 It'll request multiple columns at once, and use GETBULK if possible.  A
	 few options may be specified by passing in an OPTIONS hash containing
	 various parameters:

	 noindexes => 1
	     Instructs the code not to parse the indexes and place the results
	     in the second hash.  If you don't need the index data, this will be
	     faster.

	 columns => [ colname1, ... ]
	     This specifies which columns to collect.  By default, it will try
	     to collect all the columns defined in the MIB table.

	 repeat => COUNT
	     Specifies a GETBULK repeat COUNT.	IE, it will request this many
	     varbinds back per column when using the GETBULK operation.  Short-
	     ening this will mean smaller packets which may help going through
	     some systems.  By default, this value is calculated and attempts to
	     guess at what will fit all the results into 1000 bytes.  This cal-
	     culation is fairly safe, hopefully, but you can either raise or
	     lower the number using this option if desired.  In lossy networks,
	     you want to make sure that the packets don't get fragmented and
	     lowering this value is one way to help that.

	 nogetbulk => 1
	     Force the use of GETNEXT rather than GETBULK.  (always true for SN-
	     MPv1, as it doesn't have GETBULK anyway).	Some agents are great
	     implementers of GETBULK and this allows you to force the use of
	     GETNEXT operations instead.

	 callback => \&subroutine
	 callback => [\&subroutine, optarg1, optarg2, ...]
	     If a callback is specified, gettable will return quickly without
	     returning results.  When the results are finally retrieved the
	     callback subroutine will be called (see the other sections defining
	     callback behaviour and how to make use of SNMP::MainLoop which is
	     required for this to work).  An additional argument of the normal
	     hash result will be added to the callback subroutine arguments.

	     Note 1: internally, the gettable function uses it's own callbacks
	     which are passed to getnext/getbulk as appropriate.

	     Note 2: callback support is only available in the SNMP module ver-
	     sion 5.04 and above.  To test for this in code intending to support
	     both versions prior to 5.04 and 5.04 and up, the following should
	     work:

	       if ($response = $sess->gettable('ifTable', callback => \&my_sub)) {
		   # got a response, gettable doesn't support callback
		   my_sub($response);
		   $no_mainloop = 1;
	       }

	     Deciding on whether to use SNMP::MainLoop is left as an exercise to
	     the reader since it depends on whether your code uses other call-
	     backs as well.

SNMP::TrapSession
     $sess = new SNMP::Session(DestHost => 'host', ...)

     supports all applicable fields from SNMP::Session (see above)

   SNMP::TrapSession methods
     $sess->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

     trap(oid, uptime, <vars>) - v2 format
	     $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.inter-
		 net.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 opera-
	     tions 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

	     NULLperl 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 al-
	     ready 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 up-
	 dated 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::MainLoop([<timeout>, [<callback>]])
	 to be used with async SNMP::Session calls. MainLoop must be called af-
	 ter initial async calls so return packets from the agent will be
	 processed.  If no args supplied this function enters an infinite loop
	 so program must be exited in a callback or externally interrupted. If
	 <timeout(sic)

     &SNMP::finish()
	 This function, when called from an SNMP::MainLoop() callback function,
	 will cause the current SNMP::MainLoop() to return after the callback is
	 completed.  finish() can be used to terminate an otherwise-infinite
	 MainLoop.  A new MainLoop() instance can then be started to handle fur-
	 ther requests.

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 ses-
	 sion 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 out-
	 put, 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 identi-
	 fiers. see translateObj. will also influence the formatting of <tag> in
	 varbinds returned from 'getnext' operations. Can be set on a per ses-
	 sion basis (UseLongNames)

     $SNMP::use_sprint_value
	 default '0', set to non-zero to enable formatting of response values
	 using the snmp libraries snprint_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 to '0',set to non-zero to have <tags> for 'get' methods re-
	 turned as numeric OID's rather than descriptions.  UseLongNames will be
	 set so that the entire OID will be returned.  Set on a per-session ba-
	 sis (see UseNumeric).

     $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 ac-
	 cess lookup (defined as -IR in snmpcmd).  Can also be set on a per ses-
	 sion basis (see BestGuess)

     $SNMP::save_descriptions
	 default '0',set non-zero to have mib parser save attribute descrip-
	 tions. 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::register_debug_tokens()
	 Allows to register one or more debug tokens, just like the -D option of
	 snmpd.  Each debug token enables a group of debug statements. An exam-
	 ple: SNMP::register_debug_tokens("tdomain,netsnmp_unix");

%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 quali-
     fied 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)

     typereturns application type (see getType for values)

     access
	 returns ACCESS (ReadOnly, ReadWrite, WriteOnly, NoAccess, Notify, Cre-
	 ate)

     status
	 returns STATUS (Mandatory, Optional, Obsolete, Deprecated)

     syntax
	 returns 'textualConvention' if defined else 'type'

     textualConvention
	 returns TEXTUAL-CONVENTION

     TCDescription
	 returns the TEXTUAL-CONVENTION's DESCRIPTION field.

     units
	 returns UNITS

     hintreturns HINT

     enums
	 returns hash ref {tag => num, ...}

     ranges
	 returns array ref of hash ref [{low => num, high => num}, ...]

     description
	 returns DESCRIPTION ($SNMP::save_descriptions must be set prior to MIB
	 initialization/parsing)

     reference
	 returns the REFERENCE clause

     indexes
	 returns the objects in the INDEX clause

     implied
	 returns true if the last object in the INDEX is IMPLIED

MIB Functions
     &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 init_mib function if Mib not already loaded - does noth-
	 ing if Mib already loaded. will parse directories and load modules ac-
	 cording 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 direc-
	 tory(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 enumertion tag defined in Mib or converts tag
	 to integer depending on input. the function will return the correspond-
	 ing 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);

Exported SNMP utility functions
     Note: utility functions do not support async operation yet.

     &snmp_get()
	 takes args of SNMP::Session::new followed by those of SNMP::Ses-
	 sion::get

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

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

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

Trouble Shooting
     If problems occur there are number areas to look at to narrow down the pos-
     sibilities.

     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 enviroment variables are set appro-
     priately (see man mib_api)

     Be sure to remove old net-snmp installations and ensure headers and li-
     braries from old CMU installations are not being used by mistake.

     If the problem occurs during compilation/linking check that the snmp li-
     brary 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
     net-snmp-users@net-snmp-users@lists.sourceforge.net

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

Acknowledgements
     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 in-
     cluded - 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.

AUTHOR
     bugs, comments, questions to net-snmp-users@lists.sourceforge.net

Copyright
	  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.

perl v5.42.3			   2025-12-23				 SNMP(3)

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