public function neighbourAddresses()
    {
        $addresses = $this->getSNMP()->subOidWalk( self::OID_CDP_CACHE_NEIGHBOUR_ADDRESS, 15 );

        foreach( $addresses as $portId => $address )
        {
            if( strlen( $address ) == 8 && $this->neighbourAddressTypes()[ $portId ] == self::CDP_CACHE_NEIGHBOUR_ADDRESS_TYPE_IP )
                $addresses[ $portId ] = long2ip( hexdec( $address ) );
        }

        return $addresses;
    }