SNMP::Info::CDP(3)

NAME
SNMP::Info::CDP - SNMP Interface to Cisco Discovery Protocol (CDP) using SNMP

AUTHOR
Max Baker

SYNOPSIS
 my $cdp = new SNMP::Info (
                             AutoSpecify => 1,
                             Debug       => 1,
                             DestHost    => 'router',
                             Community   => 'public',
                             Version     => 2
                           );

 my $class = $cdp->class();
 print " Using device sub class : $class\n";

 $hascdp   = $cdp->hasCDP() ? 'yes' : 'no';

 # Print out a map of device ports with CDP neighbors:
 my $interfaces   = $cdp->interfaces();
 my $cdp_if       = $cdp->cdp_if();
 my $cdp_ip       = $cdp->cdp_ip();
 my $cdp_port     = $cdp->cdp_port();

 foreach my $cdp_key (keys %$cdp_ip){
    my $iid           = $cdp_if->{$cdp_key};
    my $port          = $interfaces->{$iid};
    my $neighbor      = $cdp_ip->{$cdp_key};
    my $neighbor_port = $cdp_port->{$cdp_key};
    print "Port : $port connected to $neighbor / $neighbor_port\n";
 }

DESCRIPTION
SNMP::Info::CDP is a subclass of SNMP::Info that provides an object oriented interface to CDP information through SNMP.

CDP is a Layer 2 protocol that supplies topology information of devices that also speak CDP, mostly switches and routers. CDP is implemented by Cisco and several other vendors.

Create or use a device subclass that inherits this class. Do not use directly.

Each device implements a subset of the global and cache entries. Check the return value to see if that data is held by the device.

  Inherited Classes
None.

  Required MIBs

CISCO-CDP-MIB

GLOBALS
These are methods that return scalar values from SNMP

$cdp->hasCDP()
    Is CDP is active in this device?

    Accounts for SNMP version 1 devices which may have CDP but not cdp_run()

$cdp->cdp_run()
    Is CDP enabled on this device? Note that a lot of Cisco devices that implement CDP don't implement this value. @#%$!

    ("cdpGlobalRun")

$cdp->cdp_interval()
    Interval in seconds at which CDP messages are generated.

    ("cdpGlobalMessageInterval")

$cdp->cdp_holdtime()
    Time in seconds that CDP messages are kept.

    ("cdpGlobalHoldTime")

$cdp->cdp_gid()
    Returns CDP device ID.

    This is the device id broadcast via CDP to other devices, and is what is retrieved from remote devices with $cdp->id().

    ("cdpGlobalDeviceId")

TABLE METHODS
These are methods that return tables of information in the form of a reference to a hash.

  CDP CACHE ENTRIES

$cdp->cdp_capabilities()
    Returns Device Functional Capabilities. Results are munged into an ascii binary string, MSB. Each digit represents a bit from the table below from the CDP Capabilities Mapping to Smartport Type table within the Cisco Small Business 200 Series Smart Switch Administration Guide, <http://www.cisco.com/c/en/us/support/switches/small-business-200-series-smart-switches/products-maintenance-guides-list.html>:

    (Bit) - Description

    (0x400) - Two-Port MAC Relay.
    (0x200) - CAST Phone Port / CVTA / Supports-STP-Dispute depending upon platform.
    (0x100) - Remotely-Managed Device.
    (0x80)  - VoIP Phone.
    (0x40)  - Provides level 1 functionality.
    (0x20)  - The bridge or switch does not forward IGMP Report packets on non router ports.
    (0x10)  - Sends and receives packets for at least one network layer protocol. If the device is routing the protocol, this bit should not be set.
    (0x08)  - Performs level 2 switching. The difference between this bit and bit 0x02 is that a switch does not run the Spanning-Tree Protocol. This device is assumed to be deployed in a physical loop-free topology.
    (0x04)  - Performs level 2 source-route bridging. A source-route bridge would set both this bit and bit 0x02.
    (0x02)  - Performs level 2 transparent bridging.
    (0x01)  - Performs level 3 routing for at least one network layer protocol.

    Thanks to Martin Lorensen for a pointer to the original information and CPAN user Alex for updates.

    ("cdpCacheCapabilities")

$cdp->cdp_domain()
    Returns remote VTP Management Domain as defined in "CISCO-VTP-MIB::managementDomainName"

    ("cdpCacheVTPMgmtDomain")

$cdp->cdp_duplex()
    Returns the port duplex status from remote devices.

    ("cdpCacheDuplex")

$cdp->cdp_id()
    Returns remote device id string

    ("cdpCacheDeviceId")

$cdp->cdp_if()
    Returns the mapping to the SNMP Interface Table.

    Note that a lot devices don't implement $cdp->cdp_index(), So if it isn't around, we fake it.

    In order to map the cdp table entry back to the interfaces() entry, we truncate the last number off of it :

      # it exists, yay.
      my $cdp_index     = $device->cdp_index();
      return $cdp_index if defined $cdp_index;

      # if not, let's fake it
      my $cdp_ip       = $device->cdp_ip();

      my %cdp_if
      foreach my $key (keys %$cdp_ip){
          $iid = $key;
          ## Truncate off .1 from cdp response
          $iid =~ s/\.\d+$//;
          $cdp_if{$key} = $iid;
      }

      return \%cdp_if;

$cdp->cdp_index()
    Returns the mapping to the SNMP2 Interface table for CDP Cache Entries.

    Most devices don't implement this, so you probably want to use $cdp->cdp_if() instead.

    See cdp_if() entry.

    ("cdpCacheIfIndex")

$cdp->cdp_ip()
    If $cdp->cdp_proto() is supported, returns remote IPV4 address only. Otherwise it will return all addresses.

    ("cdpCacheAddress")

$cdp->cdp_addr()
    Returns remote address

    ("cdpCacheAddress")

$cdp->cdp_platform()
    Returns remote platform id

    ("cdpCachePlatform")

$cdp->cdp_port()
    Returns remote Port-ID. Most of the time this is a string with the port name, but this is not guaranteed to be so.

    ("cdpCacheDevicePort")

$cdp->cdp_proto()
    Returns remote address type received. Usually IP.

    ("cdpCacheAddressType")

$cdp->cdp_ver()
    Returns remote hardware version

    ("cdpCacheVersion")

$cdp->cdp_vlan()
    Returns the remote interface native VLAN.

    ("cdpCacheNativeVLAN")

$cdp->cdp_power()
    Returns the amount of power consumed by remote device in milliwatts munged for decimal placement.

    ("cdpCachePowerConsumption")

$cdp->cdp_cap()
    Returns hash of arrays with each array containing the system capabilities supported by the remote system. Possible elements in the array are "Router", "Trans-Bridge", "Source-Route-Bridge", "Switch", "Host", "IGMP", "Repeater", "VoIP-Phone", "Remotely-Managed-Device", "Supports-STP-Dispute", and "Two-port Mac Relay".

Data Munging Callback Subroutines

$cdp->munge_power()
    Inserts a decimal at the proper location.