Karl Gaissmaier > Net-SNMP-Mixin-Dot1abLldp-0.12 > Net::SNMP::Mixin::Dot1abLldp



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Net::SNMP::Mixin::Dot1abLldp - mixin class for the Link Layer Discovery Protocol


A Net::SNMP mixin class for LLDP (Link Layer Discovery Protocol) based info.

  use Net::SNMP;
  use Net::SNMP::Mixin;


  my $session = Net::SNMP->session( -hostname => 'foo.bar.com' );


  die $session->errors if $session->errors;

  printf "Local ChassisID: %s\n",

  $lldp_loc_port_tbl = $session->get_lldp_loc_port_table;
  $lldp_rem_tbl      = $session->get_lldp_rem_table;

  foreach $lport ( keys %$lldp_rem_tbl ) {
    foreach $idx ( keys %{ $lldp_rem_tbl->{$lport} } ) {
      my $lldpRemSysName   = $lldp_rem_tbl->{$lport}{$idx}{lldpRemSysName};
      my $lldpRemPortId    = $lldp_rem_tbl->{$lport}{$idx}{lldpRemPortId};
      my $lldpRemPortDesc  = $lldp_rem_tbl->{$lport}{$idx}{lldpRemPortDesc};
      my $lldpRemChassisId = $lldp_rem_tbl->{$lport}{$idx}{lldpRemChassisId};
      my $ldesc            = $lldp_loc_port_tbl->{$lport}{lldpLocPortDesc};

      printf "$lport:$ldesc => $lldpRemSysName:$lldpRemPortId:$lldpRemPortDesc:$lldpRemChassisId\n";


With this mixin it's simple to explore the Layer-2 topologie of the network.

The LLDP (Link Layer Discovery Protocol) is an IEEE (Draft?) standard for vendor-independent Layer-2 discovery, similar to the proprietary CDP (Cisco Discovery Protocol) from Cisco. It's defined in the IEEE 802.1AB documents, therefore the name of this module.

This mixin reads data from the lldpLocalSystemData, lldpLocPortTable and the lldpRemTable out of the LLDP-MIB. At least these values are in the mandatory set of the LLDP-MIB.



Returns the LLDP lldpLocalSystemData group as a hash reference:

    lldpLocChassisIdSubtype => Integer,
    lldpLocChassisId        => OCTET_STRING,
    lldpLocSysName          => OCTET_STRING,
    lldpLocSysDesc          => OCTET_STRING,
    lldpLocSysCapSupported  => BITS,
    lldpLocSysCapEnabled    => BITS,


Returns the LLDP lldp_loc_port_table as a hash reference. The table is indexed by the LLDP local port numbers:

     lldpLocPortNum => {
        lldpLocPortIdSubtype => INTEGER,
        lldpLocPortId        => OCTET_STRING,
        lldpLocPortDesc      => OCTET_STRING,

The LLDP portnumber isn't necessarily the ifIndex of the switch. See the TEXTUAL-CONVENTION from the LLDP-MIB:

  "A port number has no mandatory relationship to an
  InterfaceIndex object (of the interfaces MIB, IETF RFC 2863).
  If the LLDP agent is a IEEE 802.1D, IEEE 802.1Q bridge, the
  LldpPortNumber will have the same value as the dot1dBasePort
  object (defined in IETF RFC 1493) associated corresponding
  bridge port.  If the system hosting LLDP agent is not an
  IEEE 802.1D or an IEEE 802.1Q bridge, the LldpPortNumber
  will have the same value as the corresponding interface's
  InterfaceIndex object."

See also the Net::SNMP::Mixin::Dot1dBase for a mixin to get the mapping between the ifIndexes and the dot1dBasePorts if needed.


Returns the LLDP lldp_rem_table as a hash reference. The table is indexed by the LLDP local port numbers on which the remote system information is received and an index for multiple neighbors on one port:

    lldpRemLocalPortNum => {
      lldpRemIndex => {
        lldpRemChassisIdSubtype => INTEGER,
        lldpRemChassisId        => OCTET_STRING,
        lldpRemPortIdSubtype    => INTEGER,
        lldpRemPortId           => OCTET_STRING,
        lldpRemPortDesc         => OCTET_STRING,
        lldpRemSysName          => OCTET_STRING,
        lldpRemSysDesc          => OCTET_STRING,
        lldpRemSysCapSupported  => BITS,
        lldpRemSysCapEnabled    => BITS,



Fetch the LLDP related snmp values from the host. Don't call this method direct!


Only for developers or maintainers.


Fetch the local system data from the lldpMIB once during object initialization.


The callback for _fetch_lldp_local_system_data.


Fetch the lldpLocPortTable once during object initialization.


The callback for _fetch_lldp_loc_port_tbl_cb().


Fetch the lldpRemTable once during object initialization.


The callback for _fetch_lldp_rem_tbl_cb().




Net::SNMP, Net::SNMP::Mixin


There are no known bugs at the time of this release. However, if you spot a bug or are experiencing difficulties that are not explained within the POD documentation, please submit a bug to the RT system (see link below). However, it would help greatly if you are able to pinpoint problems or even supply a patch.

Fixes are dependant upon their severity and my availablity. Should a fix not be forthcoming, please feel free to (politely) remind me by sending an email to gaissmai@cpan.org .

  RT: http://rt.cpan.org/Public/Dist/Display.html?Name=Net-SNMP-Mixin-Dot1abLldp


Karl Gaissmaier <karl.gaissmaier at uni-ulm.de>


Copyright 2008-2012 Karl Gaissmaier, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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