Provided by: libsnmp-info-perl_2.06-1_all bug


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


       Max Baker


        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 $c_if       = $cdp->c_if();
        my $c_ip       = $cdp->c_ip();
        my $c_port     = $cdp->c_port();

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


       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 in Cisco and some HP devices.

       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

   Required MIBs

       MIBs can be found at


       These are methods that return scalar values from SNMP

           Is CDP is active in this device?

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

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


           Interval in seconds at which CDP messages are generated.


           Time in seconds that CDP messages are kept.


           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().



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

           Returns Device Functional Capabilities.  Results are munged into an ascii binary
           string, 7 digits long, MSB.  Each digit represents a bit from the table below.

           From <>:

           (Bit) - Description

           (0x40) - Provides level 1 functionality.
           (0x20) - The bridge or switch does not forward IGMP Report packets on non router
           (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 "martin -at-" for a pointer to this information.


           Returns remote VTP Management Domain as defined in


           Returns the port duplex status from remote devices.


           Returns remote device id string


           Returns the mapping to the SNMP Interface Table.

           Note that a lot devices don't implement $cdp->c_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 $c_index     = $device->c_index();
             return $c_index if defined $c_index;

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

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

             return \%c_if;

           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->c_if() instead.

           See c_if() entry.


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


           Returns remote address


           Returns remote platform id


           Returns remote port ID


           Returns remote address type received.  Usually IP.


           Returns remote hardware version


           Returns the remote interface native VLAN.


           Returns the amount of power consumed by remote device in milliwatts munged for decimal


Data Munging Callback Subroutines

           Inserts a decimal at the proper location.