text: """NAPALM Cisco IOS Handler."""
  # Copyright 2015 Spotify AB. All rights reserved.
  #
  # The contents of this file are licensed under the Apache License, Version 2.0
  # (the "License"); you may not use this file except in compliance with the
  # License. You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations under
  # the License.
  
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import re
  import os
  import uuid
  import socket
  import tempfile
  import copy
  
  from netmiko import ConnectHandler, FileTransfer, InLineTransfer
  from netmiko import __version__ as netmiko_version
  from napalm_base.base import NetworkDriver
  from napalm_base.exceptions import ReplaceConfigException, MergeConfigException, \
              ConnectionClosedException
  
  from napalm_base.utils import py23_compat
  import napalm_base.constants as C
  import napalm_base.helpers
  
  
  # Easier to store these as constants
  HOUR_SECONDS = 3600
  DAY_SECONDS = 24 * HOUR_SECONDS
  WEEK_SECONDS = 7 * DAY_SECONDS
  YEAR_SECONDS = 365 * DAY_SECONDS
  
  # STD REGEX PATTERNS
  IP_ADDR_REGEX = r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}"
  IPV4_ADDR_REGEX = IP_ADDR_REGEX
  IPV6_ADDR_REGEX_1 = r"::"
  IPV6_ADDR_REGEX_2 = r"[0-9a-fA-F:]{1,39}::[0-9a-fA-F:]{1,39}"
  IPV6_ADDR_REGEX_3 = r"[0-9a-fA-F]{1,3}:[0-9a-fA-F]{1,3}:[0-9a-fA-F]{1,3}:[0-9a-fA-F]{1,3}:" \
                       "[0-9a-fA-F]{1,3}:[0-9a-fA-F]{1,3}:[0-9a-fA-F]{1,3}:[0-9a-fA-F]{1,3}"
  # Should validate IPv6 address using an IP address library after matching with this regex
  IPV6_ADDR_REGEX = "(?:{}|{}|{})".format(IPV6_ADDR_REGEX_1, IPV6_ADDR_REGEX_2, IPV6_ADDR_REGEX_3)
  
  MAC_REGEX = r"[a-fA-F0-9]{4}\.[a-fA-F0-9]{4}\.[a-fA-F0-9]{4}"
  VLAN_REGEX = r"\d{1,4}"
  RE_IPADDR = re.compile(r"{}".format(IP_ADDR_REGEX))
  RE_IPADDR_STRIP = re.compile(r"({})\n".format(IP_ADDR_REGEX))
  RE_MAC = re.compile(r"{}".format(MAC_REGEX))
  
  # Period needed for 32-bit AS Numbers
  ASN_REGEX = r"[\d\.]+"
  
  IOS_COMMANDS = {
     'show_mac_address': ['show mac-address-table', 'show mac address-table'],
  }
  
  
  class IOSDriver(NetworkDriver):
      """NAPALM Cisco IOS Handler."""
  
      def __init__(self, hostname, username, password, timeout=60, optional_args=None):
          """NAPALM Cisco IOS Handler."""
          if optional_args is None:
              optional_args = {}
          self.hostname = hostname
          self.username = username
          self.password = password
          self.timeout = timeout
  
          # Retrieve file names
          self.candidate_cfg = optional_args.get('candidate_cfg', 'candidate_config.txt')
          self.merge_cfg = optional_args.get('merge_cfg', 'merge_config.txt')
          self.rollback_cfg = optional_args.get('rollback_cfg', 'rollback_config.txt')
          self.inline_transfer = optional_args.get('inline_transfer', False)
  
          # None will cause autodetection of dest_file_system
          self.dest_file_system = optional_args.get('dest_file_system', None)
          self.auto_rollback_on_error = optional_args.get('auto_rollback_on_error', True)
  
          # Netmiko possible arguments
          netmiko_argument_map = {
              'port': None,
              'secret': '',
              'verbose': False,
              'keepalive': 30,
              'global_delay_factor': 1,
              'use_keys': False,
              'key_file': None,
              'ssh_strict': False,
              'system_host_keys': False,
              'alt_host_keys': False,
              'alt_key_file': '',
              'ssh_config_file': None,
          }
  
          fields = netmiko_version.split('.')
          fields = [int(x) for x in fields]
          maj_ver, min_ver, bug_fix = fields
          if maj_ver >= 2:
              netmiko_argument_map['allow_agent'] = False
          elif maj_ver == 1 and min_ver >= 1:
              netmiko_argument_map['allow_agent'] = False
  
          # Build dict of any optional Netmiko args
          self.netmiko_optional_args = {}
          for k, v in netmiko_argument_map.items():
              try:
                  self.netmiko_optional_args[k] = optional_args[k]
              except KeyError:
                  pass
          self.global_delay_factor = optional_args.get('global_delay_factor', 1)
          self.port = optional_args.get('port', 22)
  
          self.device = None
          self.config_replace = False
          self.interface_map = {}
  
          self.profile = ["ios"]
  
      def open(self):
          """Open a connection to the device."""
          self.device = ConnectHandler(device_type='cisco_ios',
                                       host=self.hostname,
                                       username=self.username,
                                       password=self.password,
                                       **self.netmiko_optional_args)
          # ensure in enable mode
          self.device.enable()
          if not self.dest_file_system:
              try:
                  self.dest_file_system = self.device._autodetect_fs()
              except AttributeError:
                  raise AttributeError("Netmiko _autodetect_fs not found please upgrade Netmiko or "
                                       "specify dest_file_system in optional_args.")
  
      def close(self):
          """Close the connection to the device."""
          self.device.disconnect()
  
      def _send_command(self, command):
          """Wrapper for self.device.send.command().
  
          If command is a list will iterate through commands until valid command.
          """
          try:
              if isinstance(command, list):
                  for cmd in command:
                      output = self.device.send_command(cmd)
                      if "% Invalid" not in output:
                          break
              else:
                  output = self.device.send_command(command)
              return self._send_command_postprocess(output)
          except (socket.error, EOFError) as e:
              raise ConnectionClosedException(str(e))
  
      def is_alive(self):
          """Returns a flag with the state of the SSH connection."""
          null = chr(0)
          try:
              # Try sending ASCII null byte to maintain
              #   the connection alive
              self.device.send_command(null)
          except (socket.error, EOFError):
              # If unable to send, we can tell for sure
              #   that the connection is unusable,
              #   hence return False.
              return {
                  'is_alive': False
              }
          return {
              'is_alive': self.device.remote_conn.transport.is_active()
          }
  
      @staticmethod
      def _create_tmp_file(config):
          """Write temp file and for use with inline config and SCP."""
          tmp_dir = tempfile.gettempdir()
          rand_fname = py23_compat.text_type(uuid.uuid4())
          filename = os.path.join(tmp_dir, rand_fname)
          with open(filename, 'wt') as fobj:
              fobj.write(config)
          return filename
  
      def _load_candidate_wrapper(self, source_file=None, source_config=None, dest_file=None,
                                  file_system=None):
          """
          Transfer file to remote device for either merge or replace operations
  
          Returns (return_status, msg)
          """
          return_status = False
          msg = ''
          if source_file and source_config:
              raise ValueError("Cannot simultaneously set source_file and source_config")
  
          if source_config:
              if self.inline_transfer:
                  (return_status, msg) = self._inline_tcl_xfer(source_config=source_config,
                                                               dest_file=dest_file,
                                                               file_system=file_system)
              else:
                  # Use SCP
                  tmp_file = self._create_tmp_file(source_config)
                  (return_status, msg) = self._scp_file(source_file=tmp_file, dest_file=dest_file,
                                                        file_system=file_system)
                  if tmp_file and os.path.isfile(tmp_file):
                      os.remove(tmp_file)
          if source_file:
              if self.inline_transfer:
                  (return_status, msg) = self._inline_tcl_xfer(source_file=source_file,
                                                               dest_file=dest_file,
                                                               file_system=file_system)
              else:
                  (return_status, msg) = self._scp_file(source_file=source_file, dest_file=dest_file,
                                                        file_system=file_system)
          if not return_status:
              if msg == '':
                  msg = "Transfer to remote device failed"
          return (return_status, msg)
  
      def load_replace_candidate(self, filename=None, config=None):
          """
          SCP file to device filesystem, defaults to candidate_config.
  
          Return None or raise exception
          """
          self.config_replace = True
          return_status, msg = self._load_candidate_wrapper(source_file=filename,
                                                            source_config=config,
                                                            dest_file=self.candidate_cfg,
                                                            file_system=self.dest_file_system)
          if not return_status:
              raise ReplaceConfigException(msg)
  
      def load_merge_candidate(self, filename=None, config=None):
          """
          SCP file to remote device.
  
          Merge configuration in: copy <file> running-config
          """
          self.config_replace = False
          return_status, msg = self._load_candidate_wrapper(source_file=filename,
                                                            source_config=config,
                                                            dest_file=self.merge_cfg,
                                                            file_system=self.dest_file_system)
          if not return_status:
              raise MergeConfigException(msg)
  
      @staticmethod
      def _normalize_compare_config(diff):
          """Filter out strings that should not show up in the diff."""
          ignore_strings = ['Contextual Config Diffs', 'No changes were found',
                            'file prompt quiet', 'ntp clock-period']
  
          new_list = []
          for line in diff.splitlines():
              for ignore in ignore_strings:
                  if ignore in line:
                      break
              else:  # nobreak
                  new_list.append(line)
          return "\n".join(new_list)
  
      @staticmethod
      def _normalize_merge_diff_incr(diff):
          """Make the compare config output look better.
  
          Cisco IOS incremental-diff output
  
          No changes:
          !List of Commands:
          end
          !No changes were found
          """
          new_diff = []
  
          changes_found = False
          for line in diff.splitlines():
              if re.search(r'order-dependent line.*re-ordered', line):
                  changes_found = True
              elif 'No changes were found' in line:
                  # IOS in the re-order case still claims "No changes were found"
                  if not changes_found:
                      return ''
                  else:
                      continue
  
              if line.strip() == 'end':
                  continue
              elif 'List of Commands' in line:
                  continue
              # Filter blank lines and prepend +sign
              elif line.strip():
                  if re.search(r"^no\s+", line.strip()):
                      new_diff.append('-' + line)
                  else:
                      new_diff.append('+' + line)
          return "\n".join(new_diff)
  
      @staticmethod
      def _normalize_merge_diff(diff):
          """Make compare_config() for merge look similar to replace config diff."""
          new_diff = []
          for line in diff.splitlines():
              # Filter blank lines and prepend +sign
              if line.strip():
                  new_diff.append('+' + line)
          if new_diff:
              new_diff.insert(0, '! incremental-diff failed; falling back to echo of merge file')
          else:
              new_diff.append('! No changes specified in merge file.')
          return "\n".join(new_diff)
  
      def compare_config(self):
          """
          show archive config differences <base_file> <new_file>.
  
          Default operation is to compare system:running-config to self.candidate_cfg
          """
          # Set defaults
          base_file = 'running-config'
          base_file_system = 'system:'
          if self.config_replace:
              new_file = self.candidate_cfg
          else:
              new_file = self.merge_cfg
          new_file_system = self.dest_file_system
  
          base_file_full = self._gen_full_path(filename=base_file, file_system=base_file_system)
          new_file_full = self._gen_full_path(filename=new_file, file_system=new_file_system)
  
          if self.config_replace:
              cmd = 'show archive config differences {} {}'.format(base_file_full, new_file_full)
              diff = self.device.send_command_expect(cmd)
              diff = self._normalize_compare_config(diff)
          else:
              # merge
              cmd = 'show archive config incremental-diffs {} ignorecase'.format(new_file_full)
              diff = self.device.send_command_expect(cmd)
              if '% Invalid' not in diff:
                  diff = self._normalize_merge_diff_incr(diff)
              else:
                  cmd = 'more {}'.format(new_file_full)
                  diff = self.device.send_command_expect(cmd)
                  diff = self._normalize_merge_diff(diff)
  
          return diff.strip()
  
      def _commit_hostname_handler(self, cmd):
          """Special handler for hostname change on commit operation."""
          try:
              current_prompt = self.device.find_prompt()
              # Wait 12 seconds for output to come back (.2 * 60)
              output = self.device.send_command_expect(cmd, delay_factor=.2, max_loops=60)
          except IOError:
              # Check if hostname change
              if current_prompt == self.device.find_prompt():
                  raise
              else:
                  self.device.set_base_prompt()
                  output = ''
          return output
  
      def commit_config(self):
          """
          If replacement operation, perform 'configure replace' for the entire config.
  
          If merge operation, perform copy <file> running-config.
          """
          # Always generate a rollback config on commit
          self._gen_rollback_cfg()
  
          if self.config_replace:
              # Replace operation
              filename = self.candidate_cfg
              cfg_file = self._gen_full_path(filename)
              if not self._check_file_exists(cfg_file):
                  raise ReplaceConfigException("Candidate config file does not exist")
              if self.auto_rollback_on_error:
                  cmd = 'configure replace {} force revert trigger error'.format(cfg_file)
              else:
                  cmd = 'configure replace {} force'.format(cfg_file)
              output = self._commit_hostname_handler(cmd)
              if ('Failed to apply command' in output) or \
                 ('original configuration has been successfully restored' in output) or \
                 ('Error' in output):
                  msg = "Candidate config could not be applied\n{}".format(output)
                  raise ReplaceConfigException(msg)
              elif '%Please turn config archive on' in output:
                  msg = "napalm-ios replace() requires Cisco 'archive' feature to be enabled."
                  raise ReplaceConfigException(msg)
          else:
              # Merge operation
              filename = self.merge_cfg
              cfg_file = self._gen_full_path(filename)
              if not self._check_file_exists(cfg_file):
                  raise MergeConfigException("Merge source config file does not exist")
              cmd = 'copy {} running-config'.format(cfg_file)
              self._disable_confirm()
              output = self._commit_hostname_handler(cmd)
              self._enable_confirm()
              if 'Invalid input detected' in output:
                  self.rollback()
                  merge_error = "Configuration merge failed; automatic rollback attempted"
                  raise MergeConfigException(merge_error)
  
          # Save config to startup (both replace and merge)
          output += self.device.send_command_expect("write mem")
  
      def discard_config(self):
          """Set candidate_cfg to current running-config. Erase the merge_cfg file."""
          discard_candidate = 'copy running-config {}'.format(self._gen_full_path(self.candidate_cfg))
          discard_merge = 'copy null: {}'.format(self._gen_full_path(self.merge_cfg))
          self._disable_confirm()
          self.device.send_command_expect(discard_candidate)
          self.device.send_command_expect(discard_merge)
          self._enable_confirm()
  
      def rollback(self):
          """Rollback configuration to filename or to self.rollback_cfg file."""
          filename = self.rollback_cfg
          cfg_file = self._gen_full_path(filename)
          if not self._check_file_exists(cfg_file):
              raise ReplaceConfigException("Rollback config file does not exist")
          cmd = 'configure replace {} force'.format(cfg_file)
          self.device.send_command_expect(cmd)
  
      def _inline_tcl_xfer(self, source_file=None, source_config=None, dest_file=None,
                           file_system=None):
          """
          Use Netmiko InlineFileTransfer (TCL) to transfer file or config to remote device.
  
          Return (status, msg)
          status = boolean
          msg = details on what happened
          """
          if source_file:
              return self._xfer_file(source_file=source_file, dest_file=dest_file,
                                     file_system=file_system, TransferClass=InLineTransfer)
          if source_config:
              return self._xfer_file(source_config=source_config, dest_file=dest_file,
                                     file_system=file_system, TransferClass=InLineTransfer)
          raise ValueError("File source not specified for transfer.")
  
      def _scp_file(self, source_file, dest_file, file_system):
          """
          SCP file to remote device.
  
          Return (status, msg)
          status = boolean
          msg = details on what happened
          """
          return self._xfer_file(source_file=source_file, dest_file=dest_file,
                                 file_system=file_system, TransferClass=FileTransfer)
  
      def _xfer_file(self, source_file=None, source_config=None, dest_file=None, file_system=None,
                     TransferClass=FileTransfer):
          """Transfer file to remote device.
  
          By default, this will use Secure Copy if self.inline_transfer is set, then will use
          Netmiko InlineTransfer method to transfer inline using either SSH or telnet (plus TCL
          onbox).
  
          Return (status, msg)
          status = boolean
          msg = details on what happened
          """
          if not source_file and not source_config:
              raise ValueError("File source not specified for transfer.")
          if not dest_file or not file_system:
              raise ValueError("Destination file or file system not specified.")
  
          if source_file:
              kwargs = dict(ssh_conn=self.device, source_file=source_file, dest_file=dest_file,
                            direction='put', file_system=file_system)
          elif source_config:
              kwargs = dict(ssh_conn=self.device, source_config=source_config, dest_file=dest_file,
                            direction='put', file_system=file_system)
          enable_scp = True
          if self.inline_transfer:
              enable_scp = False
          with TransferClass(**kwargs) as transfer:
  
              # Check if file already exists and has correct MD5
              if transfer.check_file_exists() and transfer.compare_md5():
                  msg = "File already exists and has correct MD5: no SCP needed"
                  return (True, msg)
              if not transfer.verify_space_available():
                  msg = "Insufficient space available on remote device"
                  return (False, msg)
  
              if enable_scp:
                  transfer.enable_scp()
  
              # Transfer file
              transfer.transfer_file()
  
              # Compares MD5 between local-remote files
              if transfer.verify_file():
                  msg = "File successfully transferred to remote device"
                  return (True, msg)
              else:
                  msg = "File transfer to remote device failed"
                  return (False, msg)
              return (False, '')
  
      def _enable_confirm(self):
          """Enable IOS confirmations on file operations (global config command)."""
          cmd = 'no file prompt quiet'
          self.device.send_config_set([cmd])
  
      def _disable_confirm(self):
          """Disable IOS confirmations on file operations (global config command)."""
          cmd = 'file prompt quiet'
          self.device.send_config_set([cmd])
  
      def _gen_full_path(self, filename, file_system=None):
          """Generate full file path on remote device."""
          if file_system is None:
              return '{}/{}'.format(self.dest_file_system, filename)
          else:
              if ":" not in file_system:
                  raise ValueError("Invalid file_system specified: {}".format(file_system))
              return '{}/{}'.format(file_system, filename)
  
      def _gen_rollback_cfg(self):
          """Save a configuration that can be used for rollback."""
          cfg_file = self._gen_full_path(self.rollback_cfg)
          cmd = 'copy running-config {}'.format(cfg_file)
          self._disable_confirm()
          self.device.send_command_expect(cmd)
          self._enable_confirm()
  
      def _check_file_exists(self, cfg_file):
          """
          Check that the file exists on remote device using full path.
  
          cfg_file is full path i.e. flash:/file_name
  
          For example
          # dir flash:/candidate_config.txt
          Directory of flash:/candidate_config.txt
  
          33  -rw-        5592  Dec 18 2015 10:50:22 -08:00  candidate_config.txt
  
          return boolean
          """
          cmd = 'dir {}'.format(cfg_file)
          success_pattern = 'Directory of {}'.format(cfg_file)
          output = self.device.send_command_expect(cmd)
          if 'Error opening' in output:
              return False
          elif success_pattern in output:
              return True
          return False
  
      def _expand_interface_name(self, interface_brief):
          """
          Obtain the full interface name from the abbreviated name.
  
          Cache mappings in self.interface_map.
          """
          if self.interface_map.get(interface_brief):
              return self.interface_map.get(interface_brief)
          command = 'show int {}'.format(interface_brief)
          output = self._send_command(command)
          first_line = output.splitlines()[0]
          if 'line protocol' in first_line:
              full_int_name = first_line.split()[0]
              self.interface_map[interface_brief] = full_int_name
              return self.interface_map.get(interface_brief)
          else:
              return interface_brief
  
      @staticmethod
      def _send_command_postprocess(output):
          """
          Cleanup actions on send_command() for NAPALM getters.
  
          Remove "Load for five sec; one minute if in output"
          Remove "Time source is"
          """
          output = re.sub(r"^Load for five secs.*$", "", output, flags=re.M)
          output = re.sub(r"^Time source is .*$", "", output, flags=re.M)
          return output.strip()
  
      def get_optics(self):
          command = 'show interfaces transceiver'
          output = self._send_command(command)
  
          # Check if router supports the command
          if '% Invalid input' in output:
              return {}
  
          # Formatting data into return data structure
          optics_detail = {}
  
          try:
              split_output = re.split(r'^---------.*$', output, flags=re.M)[1]
          except IndexError:
              return {}
  
          split_output = split_output.strip()
  
          for optics_entry in split_output.splitlines():
              # Example, Te1/0/1      34.6       3.29      -2.0      -3.5
              try:
                  split_list = optics_entry.split()
              except ValueError:
                  return {}
  
              int_brief = split_list[0]
              output_power = split_list[3]
              input_power = split_list[4]
  
              port = self._expand_interface_name(int_brief)
  
              port_detail = {}
  
              port_detail['physical_channels'] = {}
              port_detail['physical_channels']['channel'] = []
  
              # If interface is shutdown it returns "N/A" as output power.
              # Converting that to -100.0 float
              try:
                  float(output_power)
              except ValueError:
                  output_power = -100.0
  
              # Defaulting avg, min, max values to -100.0 since device does not
              # return these values
              optic_states = {
                  'index': 0,
                  'state': {
                      'input_power': {
                          'instant': (float(input_power) if 'input_power' else -100.0),
                          'avg': -100.0,
                          'min': -100.0,
                          'max': -100.0
                      },
                      'output_power': {
                          'instant': (float(output_power) if 'output_power' else -100.0),
                          'avg': -100.0,
                          'min': -100.0,
                          'max': -100.0
                      },
                      'laser_bias_current': {
                          'instant': 0.0,
                          'avg': 0.0,
                          'min': 0.0,
                          'max': 0.0
                      }
                  }
              }
  
              port_detail['physical_channels']['channel'].append(optic_states)
              optics_detail[port] = port_detail
  
          return optics_detail
  
      def get_lldp_neighbors(self):
          """IOS implementation of get_lldp_neighbors."""
          lldp = {}
          command = 'show lldp neighbors'
          output = self._send_command(command)
  
          # Check if router supports the command
          if '% Invalid input' in output:
              return {}
  
          # Process the output to obtain just the LLDP entries
          try:
              split_output = re.split(r'^Device ID.*$', output, flags=re.M)[1]
              split_output = re.split(r'^Total entries displayed.*$', split_output, flags=re.M)[0]
          except IndexError:
              return {}
  
          split_output = split_output.strip()
  
          for lldp_entry in split_output.splitlines():
              # Example, twb-sf-hpsw1    Fa4   120   B   17
              try:
                  device_id, local_int_brief, hold_time, capability, remote_port = lldp_entry.split()
              except ValueError:
                  if len(lldp_entry.split()) == 4:
                      # Four fields might be long_name or missing capability
                      capability_missing = True if lldp_entry[46] == ' ' else False
                      if capability_missing:
                          device_id, local_int_brief, hold_time, remote_port = lldp_entry.split()
                      else:
                          # Might be long_name issue
                          tmp_field, hold_time, capability, remote_port = lldp_entry.split()
                          device_id = tmp_field[:20]
                          local_int_brief = tmp_field[20:]
                          # device_id might be abbreviated, try to get full name
                          lldp_tmp = self._lldp_detail_parser(local_int_brief)
                          device_id_new = lldp_tmp[3][0]
                          # Verify abbreviated and full name are consistent
                          if device_id_new[:20] == device_id:
                              device_id = device_id_new
                          else:
                              raise ValueError("Unable to obtain remote device name")
              local_port = self._expand_interface_name(local_int_brief)
  
              entry = {'port': remote_port, 'hostname': device_id}
              lldp.setdefault(local_port, [])
              lldp[local_port].append(entry)
  
          return lldp
  
      def _lldp_detail_parser(self, interface):
          command = "show lldp neighbors {} detail".format(interface)
          output = self._send_command(command)
  
          # Check if router supports the command
          if '% Invalid input' in output:
              raise ValueError("Command not supported by network device")
  
          # Cisco generally use : for string divider, but sometimes has ' - '
          port_id = re.findall(r"Port id\s*?[:-]\s+(.+)", output)
          port_description = re.findall(r"Port Description\s*?[:-]\s+(.+)", output)
          chassis_id = re.findall(r"Chassis id\s*?[:-]\s+(.+)", output)
          system_name = re.findall(r"System Name\s*?[:-]\s+(.+)", output)
          system_description = re.findall(r"System Description\s*?[:-]\s*(not advertised|\s*\n.+)",
                                          output)
          system_description = [x.strip() for x in system_description]
          system_capabilities = re.findall(r"System Capabilities\s*?[:-]\s+(.+)", output)
          enabled_capabilities = re.findall(r"Enabled Capabilities\s*?[:-]\s+(.+)", output)
          remote_address = re.findall(r"Management Addresses\s*[:-]\s*(not advertised|\n.+)", output)
          # remote address had two possible patterns which required some secondary processing
          new_remote_address = []
          for val in remote_address:
              val = val.strip()
              pattern = r'(?:IP|Other)(?::\s+?)(.+)'
              match = re.search(pattern, val)
              if match:
                  new_remote_address.append(match.group(1))
              else:
                  new_remote_address.append(val)
          remote_address = new_remote_address
          return [port_id, port_description, chassis_id, system_name, system_description,
                  system_capabilities, enabled_capabilities, remote_address]
  
      def get_lldp_neighbors_detail(self, interface=''):
          """
          IOS implementation of get_lldp_neighbors_detail.
  
          Calls get_lldp_neighbors.
          """
          lldp = {}
          lldp_neighbors = self.get_lldp_neighbors()
  
          # Filter to specific interface
          if interface:
              lldp_data = lldp_neighbors.get(interface)
              if lldp_data:
                  lldp_neighbors = {interface: lldp_data}
              else:
                  lldp_neighbors = {}
  
          for interface in lldp_neighbors:
              local_port = interface
              lldp_fields = self._lldp_detail_parser(interface)
              # Convert any 'not advertised' to 'N/A'
              for field in lldp_fields:
                  for i, value in enumerate(field):
                      if 'not advertised' in value:
                          field[i] = 'N/A'
              number_entries = len(lldp_fields[0])
  
              # re.findall will return a list. Make sure same number of entries always returned.
              for test_list in lldp_fields:
                  if len(test_list) != number_entries:
                      raise ValueError("Failure processing show lldp neighbors detail")
  
              # Standardize the fields
              port_id, port_description, chassis_id, system_name, system_description, \
                  system_capabilities, enabled_capabilities, remote_address = lldp_fields
              standardized_fields = zip(port_id, port_description, chassis_id, system_name,
                                        system_description, system_capabilities,
                                        enabled_capabilities, remote_address)
  
              lldp.setdefault(local_port, [])
              for entry in standardized_fields:
                  remote_port_id, remote_port_description, remote_chassis_id, remote_system_name, \
                      remote_system_description, remote_system_capab, remote_enabled_capab, \
                      remote_mgmt_address = entry
  
                  lldp[local_port].append({
                      'parent_interface': u'N/A',
                      'remote_port': remote_port_id,
                      'remote_port_description': remote_port_description,
                      'remote_chassis_id': remote_chassis_id,
                      'remote_system_name': remote_system_name,
                      'remote_system_description': remote_system_description,
                      'remote_system_capab': remote_system_capab,
                      'remote_system_enable_capab': remote_enabled_capab})
  
          return lldp
  
      @staticmethod
      def parse_uptime(uptime_str):
          """
          Extract the uptime string from the given Cisco IOS Device.
  
          Return the uptime in seconds as an integer
          """
          # Initialize to zero
          (years, weeks, days, hours, minutes) = (0, 0, 0, 0, 0)
  
          uptime_str = uptime_str.strip()
          time_list = uptime_str.split(',')
          for element in time_list:
              if re.search("year", element):
                  years = int(element.split()[0])
              elif re.search("week", element):
                  weeks = int(element.split()[0])
              elif re.search("day", element):
                  days = int(element.split()[0])
              elif re.search("hour", element):
                  hours = int(element.split()[0])
              elif re.search("minute", element):
                  minutes = int(element.split()[0])
  
          uptime_sec = (years * YEAR_SECONDS) + (weeks * WEEK_SECONDS) + (days * DAY_SECONDS) + \
                       (hours * 3600) + (minutes * 60)
          return uptime_sec
  
      def get_facts(self):
          """Return a set of facts from the devices."""
          # default values.
          vendor = u'Cisco'
          uptime = -1
          serial_number, fqdn, os_version, hostname = (u'Unknown', u'Unknown', u'Unknown', u'Unknown')
  
          # obtain output from device
          show_ver = self._send_command('show version')
          show_hosts = self._send_command('show hosts')
          show_ip_int_br = self._send_command('show ip interface brief')
  
          # uptime/serial_number/IOS version
          for line in show_ver.splitlines():
              if ' uptime is ' in line:
                  hostname, uptime_str = line.split(' uptime is ')
                  uptime = self.parse_uptime(uptime_str)
                  hostname = hostname.strip()
  
              if 'Processor board ID' in line:
                  _, serial_number = line.split("Processor board ID ")
                  serial_number = serial_number.strip()
  
              if re.search(r"Cisco IOS Software", line):
                  try:
                      _, os_version = line.split("Cisco IOS Software, ")
                  except ValueError:
                      # Handle 'Cisco IOS Software [Denali],'
                      _, os_version = re.split(r"Cisco IOS Software \[.*?\], ", line)
                  os_version = os_version.strip()
              elif re.search(r"IOS (tm).+Software", line):
                  _, os_version = line.split("IOS (tm) ")
                  os_version = os_version.strip()
  
          # Determine domain_name and fqdn
          for line in show_hosts.splitlines():
              if 'Default domain' in line:
                  _, domain_name = line.split("Default domain is ")
                  domain_name = domain_name.strip()
                  break
          if domain_name != 'Unknown' and hostname != 'Unknown':
              fqdn = u'{}.{}'.format(hostname, domain_name)
  
          # model filter
          try:
              match_model = re.search(r"Cisco (.+?) .+bytes of", show_ver, flags=re.IGNORECASE)
              model = match_model.group(1)
          except AttributeError:
              model = u'Unknown'
  
          # interface_list filter
          interface_list = []
          show_ip_int_br = show_ip_int_br.strip()
          for line in show_ip_int_br.splitlines():
              if 'Interface ' in line:
                  continue
              interface = line.split()[0]
              interface_list.append(interface)
  
          return {
              'uptime': uptime,
              'vendor': vendor,
              'os_version': py23_compat.text_type(os_version),
              'serial_number': py23_compat.text_type(serial_number),
              'model': py23_compat.text_type(model),
              'hostname': py23_compat.text_type(hostname),
              'fqdn': fqdn,
              'interface_list': interface_list
          }
  
      def get_interfaces(self):
          """
          Get interface details.
  
          last_flapped is not implemented
  
          Example Output:
  
          {   u'Vlan1': {   'description': u'N/A',
                        'is_enabled': True,
                        'is_up': True,
                        'last_flapped': -1.0,
                        'mac_address': u'a493.4cc1.67a7',
                        'speed': 100},
          u'Vlan100': {   'description': u'Data Network',
                          'is_enabled': True,
                          'is_up': True,
                          'last_flapped': -1.0,
                          'mac_address': u'a493.4cc1.67a7',
                          'speed': 100},
          u'Vlan200': {   'description': u'Voice Network',
                          'is_enabled': True,
                          'is_up': True,
                          'last_flapped': -1.0,
                          'mac_address': u'a493.4cc1.67a7',
                          'speed': 100}}
          """
          # default values.
          last_flapped = -1.0
  
          command = 'show interfaces'
          output = self._send_command(command)
  
          interface = description = mac_address = speed = speedformat = ''
          is_enabled = is_up = None
  
          interface_dict = {}
          for line in output.splitlines():
  
              interface_regex = r"^(\S+?)\s+is\s+(.+?),\s+line\s+protocol\s+is\s+(\S+)"
              if re.search(interface_regex, line):
                  interface_match = re.search(interface_regex, line)
                  interface = interface_match.groups()[0]
                  status = interface_match.groups()[1]
                  protocol = interface_match.groups()[2]
  
                  if 'admin' in status:
                      is_enabled = False
                  else:
                      is_enabled = True
                  is_up = bool('up' in protocol)
  
              mac_addr_regex = r"^\s+Hardware.+address\s+is\s+({})".format(MAC_REGEX)
              if re.search(mac_addr_regex, line):
                  mac_addr_match = re.search(mac_addr_regex, line)
                  mac_address = napalm_base.helpers.mac(mac_addr_match.groups()[0])
  
              descr_regex = "^\s+Description:\s+(.+?)$"
              if re.search(descr_regex, line):
                  descr_match = re.search(descr_regex, line)
                  description = descr_match.groups()[0]
  
              speed_regex = r"^\s+MTU\s+\d+.+BW\s+(\d+)\s+([KMG]?b)"
              if re.search(speed_regex, line):
                  speed_match = re.search(speed_regex, line)
                  speed = speed_match.groups()[0]
                  speedformat = speed_match.groups()[1]
                  speed = float(speed)
                  if speedformat.startswith('Kb'):
                      speed = speed / 1000.0
                  elif speedformat.startswith('Gb'):
                      speed = speed * 1000
                  speed = int(round(speed))
  
                  if interface == '':
                      raise ValueError("Interface attributes were \
                                        found without any known interface")
                  if not isinstance(is_up, bool) or not isinstance(is_enabled, bool):
                      raise ValueError("Did not correctly find the interface status")
  
                  interface_dict[interface] = {'is_enabled': is_enabled, 'is_up': is_up,
                                               'description': description, 'mac_address': mac_address,
                                               'last_flapped': last_flapped, 'speed': speed}
  
                  interface = description = mac_address = speed = speedformat = ''
                  is_enabled = is_up = None
  
          return interface_dict
  
      def get_interfaces_ip(self):
          """
          Get interface ip details.
  
          Returns a dict of dicts
  
          Example Output:
  
          {   u'FastEthernet8': {   'ipv4': {   u'10.66.43.169': {   'prefix_length': 22}}},
              u'Loopback555': {   'ipv4': {   u'192.168.1.1': {   'prefix_length': 24}},
                                  'ipv6': {   u'1::1': {   'prefix_length': 64},
                                              u'2001:DB8:1::1': {   'prefix_length': 64},
                                              u'2::': {   'prefix_length': 64},
                                              u'FE80::3': {   'prefix_length': u'N/A'}}},
              u'Tunnel0': {   'ipv4': {   u'10.63.100.9': {   'prefix_length': 24}}},
              u'Tunnel1': {   'ipv4': {   u'10.63.101.9': {   'prefix_length': 24}}},
              u'Vlan100': {   'ipv4': {   u'10.40.0.1': {   'prefix_length': 24},
                                          u'10.41.0.1': {   'prefix_length': 24},
                                          u'10.65.0.1': {   'prefix_length': 24}}},
              u'Vlan200': {   'ipv4': {   u'10.63.176.57': {   'prefix_length': 29}}}}
          """
          interfaces = {}
  
          command = 'show ip interface brief'
          output = self._send_command(command)
          for line in output.splitlines():
              if 'Interface' in line and 'Status' in line:
                  continue
              fields = line.split()
              if len(fields) >= 3:
                  interface = fields[0]
              else:
                  raise ValueError("Unexpected response from the router")
              interfaces.update({interface: {}})
  
          # Parse IP Address and Subnet Mask from Interfaces
          for interface in interfaces:
              show_command = "show run interface {0}".format(interface)
              interface_output = self._send_command(show_command)
              for line in interface_output.splitlines():
                  if 'ip address ' in line and 'no ip address' not in line:
                      fields = line.split()
                      if len(fields) == 3:
                          # Check for 'ip address dhcp', convert to ip address and mask
                          if fields[2] == 'dhcp':
                              cmd = "show interface {} | in Internet address is".format(interface)
                              show_int = self._send_command(cmd)
                              int_fields = show_int.split()
                              ip_address, subnet = int_fields[3].split(r'/')
                              interfaces[interface]['ipv4'] = {ip_address: {}}
                              try:
                                  val = {'prefix_length': int(subnet)}
                              except ValueError:
                                  val = {'prefix_length': u'N/A'}
                              interfaces[interface]['ipv4'][ip_address] = val
                      elif len(fields) in [4, 5]:
                          # Check for 'ip address 10.10.10.1 255.255.255.0'
                          # Check for 'ip address 10.10.11.1 255.255.255.0 secondary'
                          if 'ipv4' not in interfaces[interface].keys():
                              interfaces[interface].update({'ipv4': {}})
                          ip_address = fields[2]
  
                          try:
                              subnet = sum([bin(int(x)).count('1') for x in fields[3].split('.')])
                          except ValueError:
                              subnet = u'N/A'
  
                          ip_dict = {'prefix_length': subnet}
                          interfaces[interface]['ipv4'].update({ip_address: {}})
                          interfaces[interface]['ipv4'][ip_address].update(ip_dict)
                      else:
                          raise ValueError(u"Unexpected Response from the device")
  
                  # Check IPv6
                  if 'ipv6 address ' in line:
                      fields = line.split()
                      ip_address = fields[2]
                      if 'ipv6' not in interfaces[interface].keys():
                              interfaces[interface].update({'ipv6': {}})
  
                      try:
                          if r'/' in ip_address:
                              # check for 'ipv6 address 1::1/64'
                              ip_address, subnet = ip_address.split(r'/')
                              interfaces[interface]['ipv6'].update({ip_address: {}})
                              ip_dict = {'prefix_length': int(subnet)}
                          else:
                              # check for 'ipv6 address FE80::3 link-local'
                              interfaces[interface]['ipv6'].update({ip_address: {}})
                              ip_dict = {'prefix_length': u'N/A'}
  
                          interfaces[interface]['ipv6'][ip_address].update(ip_dict)
                      except AttributeError:
                          raise ValueError(u"Unexpected Response from the device")
  
          # remove keys with no data
          new_interfaces = {}
          for k, val in interfaces.items():
              if val:
                  new_interfaces[k] = val
          return new_interfaces
  
      @staticmethod
      def bgp_time_conversion(bgp_uptime):
          """
          Convert string time to seconds.
  
          Examples
          00:14:23
          00:13:40
          00:00:21
          00:00:13
          00:00:49
          1d11h
          1d17h
          1w0d
          8w5d
          1y28w
          never
          """
          bgp_uptime = bgp_uptime.strip()
          uptime_letters = set(['w', 'h', 'd'])
  
          if 'never' in bgp_uptime:
              return -1
          elif ':' in bgp_uptime:
              times = bgp_uptime.split(":")
              times = [int(x) for x in times]
              hours, minutes, seconds = times
              return (hours * 3600) + (minutes * 60) + seconds
          # Check if any letters 'w', 'h', 'd' are in the time string
          elif uptime_letters & set(bgp_uptime):
              form1 = r'(\d+)d(\d+)h'  # 1d17h
              form2 = r'(\d+)w(\d+)d'  # 8w5d
              form3 = r'(\d+)y(\d+)w'  # 1y28w
              match = re.search(form1, bgp_uptime)
              if match:
                  days = int(match.group(1))
                  hours = int(match.group(2))
                  return (days * DAY_SECONDS) + (hours * 3600)
              match = re.search(form2, bgp_uptime)
              if match:
                  weeks = int(match.group(1))
                  days = int(match.group(2))
                  return (weeks * WEEK_SECONDS) + (days * DAY_SECONDS)
              match = re.search(form3, bgp_uptime)
              if match:
                  years = int(match.group(1))
                  weeks = int(match.group(2))
                  return (years * YEAR_SECONDS) + (weeks * WEEK_SECONDS)
          raise ValueError("Unexpected value for BGP uptime string: {}".format(bgp_uptime))
  
      def get_bgp_neighbors(self):
          """BGP neighbor information.
  
          Currently no VRF support. Supports both IPv4 and IPv6.
          """
          supported_afi = ['ipv4', 'ipv6']
  
          bgp_neighbor_data = dict()
          bgp_neighbor_data['global'] = {}
  
          # get summary output from device
          cmd_bgp_all_sum = 'show bgp all summary'
          summary_output = self._send_command(cmd_bgp_all_sum).strip()
  
          # get neighbor output from device
          neighbor_output = ''
          for afi in supported_afi:
              cmd_bgp_neighbor = 'show bgp %s unicast neighbors' % afi
              neighbor_output += self._send_command(cmd_bgp_neighbor).strip()
              # trailing newline required for parsing
              neighbor_output += "\n"
  
          # Regular expressions used for parsing BGP summary
          parse_summary = {
              'patterns': [
                  # For address family: IPv4 Unicast
                  {'regexp': re.compile(r'^For address family: (?P<afi>\S+) '),
                   'record': False},
                  # Capture router_id and local_as values, e.g.:
                  # BGP router identifier 10.0.1.1, local AS number 65000
                  {'regexp': re.compile(r'^.* router identifier (?P<router_id>{}), '
                                        r'local AS number (?P<local_as>{})'.format(
                                              IPV4_ADDR_REGEX, ASN_REGEX
                                        )),
                   'record': False},
                  # Match neighbor summary row, capturing useful details and
                  # discarding the 5 columns that we don't care about, e.g.:
                  # Neighbor   V          AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
                  # 10.0.0.2   4       65000 1336020 64337701 1011343614    0    0 8w0d         3143
                  {'regexp': re.compile(r'^\*?(?P<remote_addr>({})|({}))'
                                        r'\s+\d+\s+(?P<remote_as>{})(\s+\S+){{5}}\s+'
                                        r'(?P<uptime>(never)|\d+\S+)'
                                        r'\s+(?P<accepted_prefixes>\d+)'.format(
                                              IPV4_ADDR_REGEX, IPV6_ADDR_REGEX, ASN_REGEX
                                        )),
                   'record': True},
                  # Same as above, but for peer that are not Established, e.g.:
                  # Neighbor      V       AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
                  # 192.168.0.2   4    65002       0       0        1    0    0 never    Active
                  {'regexp': re.compile(r'^\*?(?P<remote_addr>({})|({}))'
                                        r'\s+\d+\s+(?P<remote_as>{})(\s+\S+){{5}}\s+'
                                        r'(?P<uptime>(never)|\d+\S+)\s+(?P<state>\D.*)'.format(
                                              IPV4_ADDR_REGEX, IPV6_ADDR_REGEX, ASN_REGEX
                                        )),
                   'record': True},
                  # ipv6 peers often break accross rows because of the longer peer address,
                  # match as above, but in separate expressions, e.g.:
                  # Neighbor      V       AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
                  # 2001:DB8::4
                  #               4    65004 9900690  612449 155362939    0    0 26w6d       36391
                  {'regexp': re.compile(r'^\*?(?P<remote_addr>({})|({}))'.format(
                                              IPV4_ADDR_REGEX, IPV6_ADDR_REGEX
                                       )),
                   'record': False},
                  {'regexp': re.compile(r'^\s+\d+\s+(?P<remote_as>{})(\s+\S+){{5}}\s+'
                                        r'(?P<uptime>(never)|\d+\S+)'
                                        r'\s+(?P<accepted_prefixes>\d+)'.format(
                                              ASN_REGEX
                                        )),
                   'record': True},
                  # Same as above, but for peers that are not Established, e.g.:
                  # Neighbor      V       AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
                  # 2001:DB8::3
                  #               4    65003       0       0        1    0    0 never    Idle (Admin)
                  {'regexp': re.compile(r'^\s+\d+\s+(?P<remote_as>{})(\s+\S+){{5}}\s+'
                                        r'(?P<uptime>(never)|\d+\S+)\s+(?P<state>\D.*)'.format(
                                              ASN_REGEX
                                        )),
                   'record': True}
              ],
              'no_fill_fields': ['accepted_prefixes', 'state', 'uptime', 'remote_as', 'remote_addr']
          }
  
          parse_neighbors = {
              'patterns': [
                  # Capture BGP neighbor is 10.0.0.2,  remote AS 65000, internal link
                  {'regexp': re.compile(r'^BGP neighbor is (?P<remote_addr>({})|({})),'
                                        r'\s+remote AS (?P<remote_as>{}).*'.format(
                                              IPV4_ADDR_REGEX, IPV6_ADDR_REGEX, ASN_REGEX
                                        )),
                   'record': False},
                  # Capture description
                  {'regexp': re.compile(r'^\s+Description: (?P<description>.+)'),
                   'record': False},
                  # Capture remote_id, e.g.:
                  # BGP version 4, remote router ID 10.0.1.2
                  {'regexp': re.compile(r'^\s+BGP version \d+, remote router ID '
                                        r'(?P<remote_id>{})'.format(IPV4_ADDR_REGEX)),
                   'record': False},
                  # Capture AFI and SAFI names, e.g.:
                  # For address family: IPv4 Unicast
                  {'regexp': re.compile(r'^\s+For address family: (?P<afi>\S+) '),
                   'record': False},
                  # Capture current sent and accepted prefixes, e.g.:
                  #     Prefixes Current:          637213       3142 (Consumes 377040 bytes)
                  {'regexp': re.compile(r'^\s+Prefixes Current:\s+(?P<sent_prefixes>\d+)\s+'
                                        r'(?P<accepted_prefixes>\d+).*'),
                   'record': False},
                  # Capture received_prefixes if soft-reconfig is enabled for the peer
                  {'regexp': re.compile(r'^\s+Saved (soft-reconfig):.+(?P<received_prefixes>\d+).*'),
                   'record': True},
                  # Otherwise, use the following as an end of row marker
                  {'regexp': re.compile(r'^\s+Local Policy Denied Prefixes:.+'),
                   'record': True}
              ],
              # fields that should not be "filled down" across table rows
              'no_fill_fields': ['received_prefixes', 'accepted_prefixes', 'sent_prefixes']
          }
  
          # Parse outputs into a list of dicts
          summary_data = []
          summary_data_entry = {}
  
          for line in summary_output.splitlines():
              # check for matches against each pattern
              for item in parse_summary['patterns']:
                  match = item['regexp'].match(line)
                  if match:
                      # a match was found, so update the temp entry with the match's groupdict
                      summary_data_entry.update(match.groupdict())
                      if item['record']:
                          # Record indicates the last piece of data has been obtained; move
                          # on to next entry
                          summary_data.append(copy.deepcopy(summary_data_entry))
                          # remove keys that are listed in no_fill_fields before the next pass
                          for field in parse_summary['no_fill_fields']:
                              try:
                                  del summary_data_entry[field]
                              except KeyError:
                                  pass
                      break
  
          neighbor_data = []
          neighbor_data_entry = {}
          for line in neighbor_output.splitlines():
              # check for matches against each pattern
              for item in parse_neighbors['patterns']:
                  match = item['regexp'].match(line)
                  if match:
                      # a match was found, so update the temp entry with the match's groupdict
                      neighbor_data_entry.update(match.groupdict())
                      if item['record']:
                          # Record indicates the last piece of data has been obtained; move
                          # on to next entry
                          neighbor_data.append(copy.deepcopy(neighbor_data_entry))
                          # remove keys that are listed in no_fill_fields before the next pass
                          for field in parse_neighbors['no_fill_fields']:
                              try:
                                  del neighbor_data_entry[field]
                              except KeyError:
                                  pass
                      break
  
          router_id = None
  
          for entry in summary_data:
              if not router_id:
                  router_id = entry['router_id']
              elif entry['router_id'] != router_id:
                  raise ValueError
  
          # check the router_id looks like an ipv4 address
          router_id = napalm_base.helpers.ip(router_id, version=4)
  
          # add parsed data to output dict
          bgp_neighbor_data['global']['router_id'] = router_id
          bgp_neighbor_data['global']['peers'] = {}
          for entry in summary_data:
              remote_addr = napalm_base.helpers.ip(entry['remote_addr'])
              afi = entry['afi'].lower()
              # check that we're looking at a supported afi
              if afi not in supported_afi:
                  continue
              # get neighbor_entry out of neighbor data
              neighbor_entry = None
              for neighbor in neighbor_data:
                  if (neighbor['afi'].lower() == afi and
                          napalm_base.helpers.ip(neighbor['remote_addr']) == remote_addr):
                      neighbor_entry = neighbor
                      break
              if not isinstance(neighbor_entry, dict):
                  raise ValueError(msg="Couldn't find neighbor data for %s in afi %s" %
                                       (remote_addr, afi))
  
              # check for admin down state
              try:
                  if "(Admin)" in entry['state']:
                      is_enabled = False
                  else:
                      is_enabled = True
              except KeyError:
                  is_enabled = True
  
              # parse uptime value
              uptime = self.bgp_time_conversion(entry['uptime'])
  
              # Uptime should be -1 if BGP session not up
              is_up = True if uptime >= 0 else False
  
              # check whether session is up for address family and get prefix count
              try:
                  accepted_prefixes = int(entry['accepted_prefixes'])
              except (ValueError, KeyError):
                  accepted_prefixes = -1
  
              # Only parse neighbor detailed data if BGP session is-up
              if is_up:
                  try:
                      # overide accepted_prefixes with neighbor data if possible (since that's newer)
                      accepted_prefixes = int(neighbor_entry['accepted_prefixes'])
                  except (ValueError, KeyError):
                      pass
  
                  # try to get received prefix count, otherwise set to accepted_prefixes
                  received_prefixes = neighbor_entry.get('received_prefixes', accepted_prefixes)
  
                  # try to get sent prefix count and convert to int, otherwise set to -1
                  sent_prefixes = int(neighbor_entry.get('sent_prefixes', -1))
              else:
                  received_prefixes = -1
                  sent_prefixes = -1
  
              # get description
              try:
                  description = py23_compat.text_type(neighbor_entry['description'])
              except KeyError:
                  description = ''
  
              # check the remote router_id looks like an ipv4 address
              remote_id = napalm_base.helpers.ip(neighbor_entry['remote_id'], version=4)
  
              if remote_addr not in bgp_neighbor_data['global']['peers']:
                  bgp_neighbor_data['global']['peers'][remote_addr] = {
                      'local_as': napalm_base.helpers.as_number(entry['local_as']),
                      'remote_as': napalm_base.helpers.as_number(entry['remote_as']),
                      'remote_id': remote_id,
                      'is_up': is_up,
                      'is_enabled': is_enabled,
                      'description': description,
                      'uptime': uptime,
                      'address_family': {
                          afi: {
                              'received_prefixes': received_prefixes,
                              'accepted_prefixes': accepted_prefixes,
                              'sent_prefixes': sent_prefixes
                          }
                      }
                  }
              else:
                  # found previous data for matching remote_addr, but for different afi
                  existing = bgp_neighbor_data['global']['peers'][remote_addr]
                  assert afi not in existing['address_family']
                  # compare with existing values and croak if they don't match
                  assert existing['local_as'] == napalm_base.helpers.as_number(entry['local_as'])
                  assert existing['remote_as'] == napalm_base.helpers.as_number(entry['remote_as'])
                  assert existing['remote_id'] == remote_id
                  assert existing['is_enabled'] == is_enabled
                  assert existing['description'] == description
                  # merge other values in a sane manner
                  existing['is_up'] = existing['is_up'] or is_up
                  existing['uptime'] = max(existing['uptime'], uptime)
                  existing['address_family'][afi] = {
                      'received_prefixes': received_prefixes,
                      'accepted_prefixes': accepted_prefixes,
                      'sent_prefixes': sent_prefixes
                  }
          return bgp_neighbor_data
  
      def get_interfaces_counters(self):
          """
          Return interface counters and errors.
  
          'tx_errors': int,
          'rx_errors': int,
          'tx_discards': int,
          'rx_discards': int,
          'tx_octets': int,
          'rx_octets': int,
          'tx_unicast_packets': int,
          'rx_unicast_packets': int,
          'tx_multicast_packets': int,
          'rx_multicast_packets': int,
          'tx_broadcast_packets': int,
          'rx_broadcast_packets': int,
  
          Currently doesn't determine output broadcasts, multicasts
          """
          counters = {}
          command = 'show interfaces'
          output = self._send_command(command)
          sh_int_sum_cmd = 'show interface summary'
          sh_int_sum_cmd_out = self._send_command(sh_int_sum_cmd)
  
          # Break output into per-interface sections
          interface_strings = re.split(r'.* line protocol is .*', output, flags=re.M)
          header_strings = re.findall(r'.* line protocol is .*', output, flags=re.M)
  
          empty = interface_strings.pop(0).strip()
          if empty:
              raise ValueError("Unexpected output from: {}".format(command))
  
          # Parse out the interface names
          intf = []
          for intf_line in header_strings:
              interface, _ = re.split(r" is .* line protocol is ", intf_line)
              intf.append(interface.strip())
  
          if len(intf) != len(interface_strings):
              raise ValueError("Unexpected output from: {}".format(command))
  
          # Re-join interface names with interface strings
          for interface, interface_str in zip(intf, interface_strings):
              counters.setdefault(interface, {})
              for line in interface_str.splitlines():
                  if 'packets input' in line:
                      # '0 packets input, 0 bytes, 0 no buffer'
                      match = re.search(r"(\d+) packets input.* (\d+) bytes", line)
                      counters[interface]['rx_unicast_packets'] = int(match.group(1))
                      counters[interface]['rx_octets'] = int(match.group(2))
                  elif 'broadcast' in line:
                      # 'Received 0 broadcasts (0 multicasts)'
                      # 'Received 264071 broadcasts (39327 IP multicasts)'
                      # 'Received 338 broadcasts, 0 runts, 0 giants, 0 throttles'
                      match = re.search(r"Received (\d+) broadcasts.*(\d+).*multicasts", line)
                      alt_match = re.search(r"Received (\d+) broadcasts.*", line)
                      if match:
                          counters[interface]['rx_broadcast_packets'] = int(match.group(1))
                          counters[interface]['rx_multicast_packets'] = int(match.group(2))
                      elif alt_match:
                          counters[interface]['rx_broadcast_packets'] = int(alt_match.group(1))
                          counters[interface]['rx_multicast_packets'] = -1
                      else:
                          counters[interface]['rx_broadcast_packets'] = -1
                          counters[interface]['rx_multicast_packets'] = -1
                  elif 'packets output' in line:
                      # '0 packets output, 0 bytes, 0 underruns'
                      match = re.search(r"(\d+) packets output.* (\d+) bytes", line)
                      counters[interface]['tx_unicast_packets'] = int(match.group(1))
                      counters[interface]['tx_octets'] = int(match.group(2))
                      counters[interface]['tx_broadcast_packets'] = -1
                      counters[interface]['tx_multicast_packets'] = -1
                  elif 'input errors' in line:
                      # '0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored'
                      match = re.search(r"(\d+) input errors", line)
                      counters[interface]['rx_errors'] = int(match.group(1))
                      counters[interface]['rx_discards'] = -1
                  elif 'output errors' in line:
                      # '0 output errors, 0 collisions, 1 interface resets'
                      match = re.search(r"(\d+) output errors", line)
                      counters[interface]['tx_errors'] = int(match.group(1))
                      counters[interface]['tx_discards'] = -1
              for line in sh_int_sum_cmd_out.splitlines():
                  if interface in line:
                      # Line is tabular output with columns
                      # Interface  IHQ  IQD  OHQ  OQD  RXBS  RXPS  TXBS  TXPS  TRTL
                      # where columns (excluding interface) are integers
                      regex = r"\b" + interface + \
                          r"\b\s+(\d+)\s+(?P<IQD>\d+)\s+(\d+)" + \
                          r"\s+(?P<OQD>\d+)\s+(\d+)\s+(\d+)" + \
                          r"\s+(\d+)\s+(\d+)\s+(\d+)"
                      match = re.search(regex, line)
                      if match:
                          counters[interface]['rx_discards'] = int(match.group("IQD"))
                          counters[interface]['tx_discards'] = int(match.group("OQD"))
  
          return counters
  
      def get_environment(self):
          """
          Get environment facts.
  
          power, fan, temperature are currently not implemented
          cpu is using 1-minute average
          cpu hard-coded to cpu0 (i.e. only a single CPU)
          """
          environment = {}
          cpu_cmd = 'show proc cpu'
          mem_cmd = 'show memory statistics'
  
          output = self._send_command(cpu_cmd)
          environment.setdefault('cpu', {})
          environment['cpu'][0] = {}
          environment['cpu'][0]['%usage'] = 0.0
          for line in output.splitlines():
              if 'CPU utilization' in line:
                  # CPU utilization for five seconds: 2%/0%; one minute: 2%; five minutes: 1%
                  cpu_regex = r'^.*one minute: (\d+)%; five.*$'
                  match = re.search(cpu_regex, line)
                  environment['cpu'][0]['%usage'] = float(match.group(1))
                  break
  
          output = self._send_command(mem_cmd)
          for line in output.splitlines():
              if 'Processor' in line:
                  _, _, _, proc_used_mem, proc_free_mem = line.split()[:5]
              elif 'I/O' in line or 'io' in line:
                  _, _, _, io_used_mem, io_free_mem = line.split()[:5]
          used_mem = int(proc_used_mem) + int(io_used_mem)
          free_mem = int(proc_free_mem) + int(io_free_mem)
          environment.setdefault('memory', {})
          environment['memory']['used_ram'] = used_mem
          environment['memory']['available_ram'] = free_mem
  
          # Initialize 'power', 'fan', and 'temperature' to default values (not implemented)
          environment.setdefault('power', {})
          environment['power']['invalid'] = {'status': True, 'output': -1.0, 'capacity': -1.0}
          environment.setdefault('fans', {})
          environment['fans']['invalid'] = {'status': True}
          environment.setdefault('temperature', {})
          env_value = {'is_alert': False, 'is_critical': False, 'temperature': -1.0}
          environment['temperature']['invalid'] = env_value
          return environment
  
      def get_arp_table(self):
          """
          Get arp table information.
  
          Return a list of dictionaries having the following set of keys:
              * interface (string)
              * mac (string)
              * ip (string)
              * age (float)
  
          For example::
              [
                  {
                      'interface' : 'MgmtEth0/RSP0/CPU0/0',
                      'mac'       : '5c:5e:ab:da:3c:f0',
                      'ip'        : '172.17.17.1',
                      'age'       : 1454496274.84
                  },
                  {
                      'interface': 'MgmtEth0/RSP0/CPU0/0',
                      'mac'       : '66:0e:94:96:e0:ff',
                      'ip'        : '172.17.17.2',
                      'age'       : 1435641582.49
                  }
              ]
          """
          arp_table = []
  
          command = 'show arp | exclude Incomplete'
          output = self._send_command(command)
  
          # Skip the first line which is a header
          output = output.split('\n')
          output = output[1:]
  
          for line in output:
              if len(line) == 0:
                  return {}
              if len(line.split()) == 5:
                  # Static ARP entries have no interface
                  # Internet  10.0.0.1                -   0010.2345.1cda  ARPA
                  interface = ''
                  protocol, address, age, mac, eth_type = line.split()
              elif len(line.split()) == 6:
                  protocol, address, age, mac, eth_type, interface = line.split()
              else:
                  raise ValueError("Unexpected output from: {}".format(line.split()))
  
              try:
                  if age == '-':
                      age = 0
                  age = float(age)
              except ValueError:
                  raise ValueError("Unable to convert age value to float: {}".format(age))
  
              # Validate we matched correctly
              if not re.search(RE_IPADDR, address):
                  raise ValueError("Invalid IP Address detected: {}".format(address))
              if not re.search(RE_MAC, mac):
                  raise ValueError("Invalid MAC Address detected: {}".format(mac))
              entry = {
                  'interface': interface,
                  'mac': napalm_base.helpers.mac(mac),
                  'ip': address,
                  'age': age
              }
              arp_table.append(entry)
          return arp_table
  
      def cli(self, commands):
          """
          Execute a list of commands and return the output in a dictionary format using the command
          as the key.
  
          Example input:
          ['show clock', 'show calendar']
  
          Output example:
          {   'show calendar': u'22:02:01 UTC Thu Feb 18 2016',
              'show clock': u'*22:01:51.165 UTC Thu Feb 18 2016'}
  
          """
          cli_output = dict()
          if type(commands) is not list:
              raise TypeError('Please enter a valid list of commands!')
  
          for command in commands:
              output = self._send_command(command)
              if 'Invalid input detected' in output:
                  raise ValueError('Unable to execute command "{}"'.format(command))
              cli_output.setdefault(command, {})
              cli_output[command] = output
  
          return cli_output
  
      def get_ntp_servers(self):
          """Implementation of get_ntp_servers for IOS.
  
          Returns the NTP servers configuration as dictionary.
          The keys of the dictionary represent the IP Addresses of the servers.
          Inner dictionaries do not have yet any available keys.
          Example::
              {
                  '192.168.0.1': {},
                  '17.72.148.53': {},
                  '37.187.56.220': {},
                  '162.158.20.18': {}
              }
          """
          ntp_servers = {}
          command = 'show run | include ntp server'
          output = self._send_command(command)
  
          for line in output.splitlines():
              split_line = line.split()
              if "vrf" == split_line[2]:
                  ntp_servers[split_line[4]] = {}
              else:
                  ntp_servers[split_line[2]] = {}
  
          return ntp_servers
  
      def get_ntp_stats(self):
          """Implementation of get_ntp_stats for IOS."""
          ntp_stats = []
  
          command = 'show ntp associations'
          output = self._send_command(command)
  
          for line in output.splitlines():
              # Skip first two lines and last line of command output
              if line == "" or 'address' in line or 'sys.peer' in line:
                  continue
  
              if '%NTP is not enabled' in line:
                  return []
  
              elif len(line.split()) == 9:
                  address, ref_clock, st, when, poll, reach, delay, offset, disp = line.split()
                  address_regex = re.match('(\W*)([0-9.*]*)', address)
              try:
                  ntp_stats.append({
                      'remote': py23_compat.text_type(address_regex.group(2)),
                      'synchronized': ('*' in address_regex.group(1)),
                      'referenceid': py23_compat.text_type(ref_clock),
                      'stratum': int(st),
                      'type': u'-',
                      'when': py23_compat.text_type(when),
                      'hostpoll': int(poll),
                      'reachability': int(reach),
                      'delay': float(delay),
                      'offset': float(offset),
                      'jitter': float(disp)
                  })
              except Exception:
                  continue
  
          return ntp_stats
  
      def get_mac_address_table(self):
          """
          Returns a lists of dictionaries. Each dictionary represents an entry in the MAC Address
          Table, having the following keys
              * mac (string)
              * interface (string)
              * vlan (int)
              * active (boolean)
              * static (boolean)
              * moves (int)
              * last_move (float)
  
          Format1:
          Destination Address  Address Type  VLAN  Destination Port
          -------------------  ------------  ----  --------------------
          6400.f1cf.2cc6          Dynamic       1     Wlan-GigabitEthernet0
  
          Cat 6500:
          Legend: * - primary entry
                  age - seconds since last seen
                  n/a - not available
  
            vlan   mac address     type    learn     age              ports
          ------+----------------+--------+-----+----------+--------------------------
          *  999  1111.2222.3333   dynamic  Yes          0   Port-channel1
             999  1111.2222.3333   dynamic  Yes          0   Port-channel1
  
          Cat 4948
          Unicast Entries
           vlan   mac address     type        protocols               port
          -------+---------------+--------+---------------------+--------------------
           999    1111.2222.3333   dynamic ip                    Port-channel1
  
          Cat 2960
          Mac Address Table
          -------------------------------------------
  
          Vlan    Mac Address       Type        Ports
          ----    -----------       --------    -----
          All    1111.2222.3333    STATIC      CPU
          """
  
          RE_MACTABLE_DEFAULT = r"^" + MAC_REGEX
          RE_MACTABLE_6500_1 = r"^\*\s+{}\s+{}\s+".format(VLAN_REGEX, MAC_REGEX)  # 7 fields
          RE_MACTABLE_6500_2 = r"^{}\s+{}\s+".format(VLAN_REGEX, MAC_REGEX)   # 6 fields
          RE_MACTABLE_6500_3 = r"^\s{51}\S+"                               # Fill down from prior
          RE_MACTABLE_4500_1 = r"^{}\s+{}\s+".format(VLAN_REGEX, MAC_REGEX)     # 5 fields
          RE_MACTABLE_4500_2 = r"^\s{32}\S+"                               # Fill down from prior
          RE_MACTABLE_2960_1 = r"^All\s+{}".format(MAC_REGEX)
          RE_MACTABLE_GEN_1 = r"^{}\s+{}\s+".format(VLAN_REGEX, MAC_REGEX)   # 4 fields (2960/4500)
  
          def process_mac_fields(vlan, mac, mac_type, interface):
              """Return proper data for mac address fields."""
              if mac_type.lower() in ['self', 'static', 'system']:
                  static = True
                  if vlan.lower() == 'all':
                      vlan = 0
                  if interface.lower() == 'cpu' or re.search(r'router', interface.lower()) or \
                          re.search(r'switch', interface.lower()):
                      interface = ''
              else:
                  static = False
              if mac_type.lower() in ['dynamic']:
                  active = True
              else:
                  active = False
              return {
                  'mac': napalm_base.helpers.mac(mac),
                  'interface': interface,
                  'vlan': int(vlan),
                  'static': static,
                  'active': active,
                  'moves': -1,
                  'last_move': -1.0
              }
  
          mac_address_table = []
          command = IOS_COMMANDS['show_mac_address']
          output = self._send_command(command)
  
          # Skip the header lines
          output = re.split(r'^----.*', output, flags=re.M)[1:]
          output = "\n".join(output).strip()
          # Strip any leading astericks
          output = re.sub(r"^\*", "", output, flags=re.M)
          fill_down_vlan = fill_down_mac = fill_down_mac_type = ''
          for line in output.splitlines():
              # Cat6500 one off anf 4500 multicast format
              if (re.search(RE_MACTABLE_6500_3, line) or re.search(RE_MACTABLE_4500_2, line)):
                  interface = line.strip()
                  if ',' in interface:
                      interfaces = interface.split(',')
                  else:
                      interfaces = []
                      interfaces.append(interface)
                  for single_interface in interfaces:
                      mac_address_table.append(process_mac_fields(fill_down_vlan, fill_down_mac,
                                                                  fill_down_mac_type,
                                                                  single_interface))
                  continue
              line = line.strip()
              if line == '':
                  continue
              if re.search(r"^---", line):
                  # Convert any '---' to VLAN 0
                  line = re.sub(r"^---", "0", line, flags=re.M)
  
              # Format1
              if re.search(RE_MACTABLE_DEFAULT, line):
                  if len(line.split()) == 4:
                      mac, mac_type, vlan, interface = line.split()
                      mac_address_table.append(process_mac_fields(vlan, mac, mac_type, interface))
                  else:
                      raise ValueError("Unexpected output from: {}".format(line.split()))
              # Cat6500 format
              elif (re.search(RE_MACTABLE_6500_1, line) or re.search(RE_MACTABLE_6500_2, line)) and \
                      len(line.split()) >= 6:
                  if len(line.split()) == 7:
                      _, vlan, mac, mac_type, _, _, interface = line.split()
                  elif len(line.split()) == 6:
                      vlan, mac, mac_type, _, _, interface = line.split()
                  if ',' in interface:
                      interfaces = interface.split(',')
                      fill_down_vlan = vlan
                      fill_down_mac = mac
                      fill_down_mac_type = mac_type
                      for single_interface in interfaces:
                          mac_address_table.append(process_mac_fields(vlan, mac, mac_type,
                                                                      single_interface))
                  else:
                      mac_address_table.append(process_mac_fields(vlan, mac, mac_type, interface))
              # Cat4500 format
              elif re.search(RE_MACTABLE_4500_1, line) and len(line.split()) == 5:
                  vlan, mac, mac_type, _, interface = line.split()
                  mac_address_table.append(process_mac_fields(vlan, mac, mac_type, interface))
              # Cat2960 format - ignore extra header line
              elif re.search(r"^Vlan\s+Mac Address\s+", line):
                  continue
              # Cat2960 format (Cat4500 format multicast entries)
              elif (re.search(RE_MACTABLE_2960_1, line) or re.search(RE_MACTABLE_GEN_1, line)) and \
                      len(line.split()) == 4:
                  vlan, mac, mac_type, interface = line.split()
                  if ',' in interface:
                      interfaces = interface.split(',')
                      fill_down_vlan = vlan
                      fill_down_mac = mac
                      fill_down_mac_type = mac_type
                      for single_interface in interfaces:
                          mac_address_table.append(process_mac_fields(vlan, mac, mac_type,
                                                                      single_interface))
                  else:
                      mac_address_table.append(process_mac_fields(vlan, mac, mac_type, interface))
              elif re.search(r"Total Mac Addresses", line):
                  continue
              elif re.search(r"Multicast Entries", line):
                  continue
              elif re.search(r"vlan.*mac.*address.*type.*", line):
                  continue
              else:
                  raise ValueError("Unexpected output from: {}".format(repr(line)))
  
          return mac_address_table
  
      def get_snmp_information(self):
          """
          Returns a dict of dicts
  
          Example Output:
  
          {   'chassis_id': u'Asset Tag 54670',
          'community': {   u'private': {   'acl': u'12', 'mode': u'rw'},
                           u'public': {   'acl': u'11', 'mode': u'ro'},
                           u'public_named_acl': {   'acl': u'ALLOW-SNMP-ACL',
                                                    'mode': u'ro'},
                           u'public_no_acl': {   'acl': u'N/A', 'mode': u'ro'}},
          'contact': u'Joe Smith',
          'location': u'123 Anytown USA Rack 404'}
  
          """
          # default values
          snmp_dict = {
              'chassis_id': u'unknown',
              'community': {},
              'contact': u'unknown',
              'location': u'unknown'
          }
          command = 'show run | include snmp-server'
          output = self._send_command(command)
          for line in output.splitlines():
              fields = line.split()
              if 'snmp-server community' in line:
                  name = fields[2]
                  if 'community' not in snmp_dict.keys():
                      snmp_dict.update({'community': {}})
                  snmp_dict['community'].update({name: {}})
                  try:
                      snmp_dict['community'][name].update({'mode': fields[3].lower()})
                  except IndexError:
                      snmp_dict['community'][name].update({'mode': u'N/A'})
                  try:
                      snmp_dict['community'][name].update({'acl': fields[4]})
                  except IndexError:
                      snmp_dict['community'][name].update({'acl': u'N/A'})
              elif 'snmp-server location' in line:
                  snmp_dict['location'] = ' '.join(fields[2:])
              elif 'snmp-server contact' in line:
                  snmp_dict['contact'] = ' '.join(fields[2:])
              elif 'snmp-server chassis-id' in line:
                  snmp_dict['chassis_id'] = ' '.join(fields[2:])
          # If SNMP Chassis wasn't found; obtain using direct command
          if snmp_dict['chassis_id'] == 'unknown':
              command = 'show snmp chassis'
              snmp_chassis = self._send_command(command)
              snmp_dict['chassis_id'] = snmp_chassis
          return snmp_dict
  
      def ping(self, destination, source=C.PING_SOURCE, ttl=C.PING_TTL, timeout=C.PING_TIMEOUT,
               size=C.PING_SIZE, count=C.PING_COUNT, vrf=C.PING_VRF):
          """
          Execute ping on the device and returns a dictionary with the result.
  
          Output dictionary has one of following keys:
              * success
              * error
          In case of success, inner dictionary will have the followin keys:
              * probes_sent (int)
              * packet_loss (int)
              * rtt_min (float)
              * rtt_max (float)
              * rtt_avg (float)
              * rtt_stddev (float)
              * results (list)
          'results' is a list of dictionaries with the following keys:
              * ip_address (str)
              * rtt (float)
          """
          ping_dict = {}
          # vrf needs to be right after the ping command
          if vrf:
              command = 'ping vrf {} {}'.format(vrf, destination)
          else:
              command = 'ping {}'.format(destination)
          command += ' timeout {}'.format(timeout)
          command += ' size {}'.format(size)
          command += ' repeat {}'.format(count)
          if source != '':
              command += ' source {}'.format(source)
  
          output = self._send_command(command)
          if '%' in output:
              ping_dict['error'] = output
          elif 'Sending' in output:
              ping_dict['success'] = {
                                  'probes_sent': 0,
                                  'probes_sent': 0,
                                  'packet_loss': 0,
                                  'rtt_min': 0.0,
                                  'rtt_max': 0.0,
                                  'rtt_avg': 0.0,
                                  'rtt_stddev': 0.0,
                                  'results': []
              }
  
              for line in output.splitlines():
                  fields = line.split()
                  if 'Success rate is 0' in line:
                      sent_and_received = re.search(r'\((\d*)/(\d*)\)', fields[5])
                      probes_sent = int(sent_and_received.groups()[0])
                      probes_received = int(sent_and_received.groups()[1])
                      ping_dict['success']['probes_sent'] = probes_sent
                      ping_dict['success']['packet_loss'] = probes_sent - probes_received
                  elif 'Success rate is' in line:
                      sent_and_received = re.search(r'\((\d*)/(\d*)\)', fields[5])
                      probes_sent = int(sent_and_received.groups()[0])
                      probes_received = int(sent_and_received.groups()[1])
                      min_avg_max = re.search(r'(\d*)/(\d*)/(\d*)', fields[9])
                      ping_dict['success']['probes_sent'] = probes_sent
                      ping_dict['success']['packet_loss'] = probes_sent - probes_received
                      ping_dict['success'].update({
                                      'rtt_min': float(min_avg_max.groups()[0]),
                                      'rtt_avg': float(min_avg_max.groups()[1]),
                                      'rtt_max': float(min_avg_max.groups()[2]),
                      })
                      results_array = []
                      for i in range(probes_received):
                          results_array.append({'ip_address': py23_compat.text_type(destination),
                                               'rtt': 0.0})
                      ping_dict['success'].update({'results': results_array})
  
          return ping_dict
  
      def traceroute(self, destination, source=C.TRACEROUTE_SOURCE,
                     ttl=C.TRACEROUTE_TTL, timeout=C.TRACEROUTE_TIMEOUT, vrf=C.TRACEROUTE_VRF):
          """
          Executes traceroute on the device and returns a dictionary with the result.
  
          :param destination: Host or IP Address of the destination
          :param source (optional): Use a specific IP Address to execute the traceroute
          :param ttl (optional): Maimum number of hops -> int (0-255)
          :param timeout (optional): Number of seconds to wait for response -> int (1-3600)
  
          Output dictionary has one of the following keys:
  
              * success
              * error
  
          In case of success, the keys of the dictionary represent the hop ID, while values are
          dictionaries containing the probes results:
              * rtt (float)
              * ip_address (str)
              * host_name (str)
          """
  
          # vrf needs to be right after the traceroute command
          if vrf:
              command = "traceroute vrf {} {}".format(vrf, destination)
          else:
              command = "traceroute {}".format(destination)
          if source:
              command += " source {}".format(source)
          if ttl:
              if isinstance(ttl, int) and 0 <= timeout <= 255:
                  command += " ttl 0 {}".format(str(ttl))
          if timeout:
              # Timeout should be an integer between 1 and 3600
              if isinstance(timeout, int) and 1 <= timeout <= 3600:
                  command += " timeout {}".format(str(timeout))
  
          # Calculation to leave enough time for traceroute to complete assumes send_command
          # delay of .2 seconds.
          max_loops = (5 * ttl * timeout) + 150
          if max_loops < 500:     # Make sure max_loops isn't set artificially low
              max_loops = 500
          output = self.device.send_command(command, max_loops=max_loops)
  
          # Prepare return dict
          traceroute_dict = dict()
          if re.search('Unrecognized host or address', output):
              traceroute_dict['error'] = 'unknown host %s' % destination
              return traceroute_dict
          else:
              traceroute_dict['success'] = dict()
  
          results = dict()
          # Find all hops
          hops = re.findall('\\n\s+[0-9]{1,3}\s', output)
          for hop in hops:
              # Search for hop in the output
              hop_match = re.search(hop, output)
              # Find the start index for hop
              start_index = hop_match.start()
              # If this is last hop
              if hops.index(hop) + 1 == len(hops):
                  # Set the stop index for hop to len of output
                  stop_index = len(output)
              # else, find the start index for next hop
              else:
                  next_hop_match = re.search(hops[hops.index(hop) + 1], output)
                  stop_index = next_hop_match.start()
                  # Now you have the start and stop index for each hop
                  # and you can parse the probes
              # Set the hop_variable, and remove spaces between msec for easier matching
              hop_string = output[start_index:stop_index].replace(' msec', 'msec')
              hop_list = hop_string.split()
              current_hop = int(hop_list.pop(0))
              # Prepare dictionary for each hop (assuming there are 3 probes in each hop)
              results[current_hop] = dict()
              results[current_hop]['probes'] = dict()
              results[current_hop]['probes'][1] = {'rtt': float(),
                                                   'ip_address': '',
                                                   'host_name': ''}
              results[current_hop]['probes'][2] = {'rtt': float(),
                                                   'ip_address': '',
                                                   'host_name': ''}
              results[current_hop]['probes'][3] = {'rtt': float(),
                                                   'ip_address': '',
                                                   'host_name': ''}
              current_probe = 1
              ip_address = ''
              host_name = ''
              while hop_list:
                  current_element = hop_list.pop(0)
                  # If current_element is * move index in dictionary to next probe
                  if current_element == '*':
                      current_probe += 1
                  # If current_element contains msec record the entry for probe
                  elif 'msec' in current_element:
                      ip_address = py23_compat.text_type(ip_address)
                      host_name = py23_compat.text_type(host_name)
                      rtt = float(current_element.replace('msec', ''))
                      results[current_hop]['probes'][current_probe]['ip_address'] = ip_address
                      results[current_hop]['probes'][current_probe]['host_name'] = host_name
                      results[current_hop]['probes'][current_probe]['rtt'] = rtt
                      # After recording the entry move the index to next probe
                      current_probe += 1
                  # If element contains '(' and ')', the output format is 'FQDN (IP_ADDRESS)'
                  # Save the IP address
                  elif '(' in current_element:
                      ip_address = current_element.replace('(', '').replace(')', '')
                  # Save the probe's ip_address and host_name
                  else:
                      host_name = current_element
                      ip_address = current_element
  
          traceroute_dict['success'] = results
          return traceroute_dict
  
      def get_config(self, retrieve='all'):
          """Implementation of get_config for IOS.
  
          Returns the startup or/and running configuration as dictionary.
          The keys of the dictionary represent the type of configuration
          (startup or running). The candidate is always empty string,
          since IOS does not support candidate configuration.
          """
  
          configs = {
              'startup': '',
              'running': '',
              'candidate': '',
          }
  
          if retrieve in ('startup', 'all'):
              command = 'show startup-config'
              output = self._send_command(command)
              configs['startup'] = output
  
          if retrieve in ('running', 'all'):
              command = 'show running-config'
              output = self._send_command(command)
              configs['running'] = output
  
          return configs
  