Diniz Martins

May 2, 20222 min

Python | Cisco details in bulk

Run Python Automation Script to fetch Cisco Routers and Switches details in Bulk.

The details includes “hostname, uptime, current version, current image, serial number, device model, device memory”

Pre-Requisite: Netmiko

About Script:

  • The script will login to each IP Address defined in ip_list

  • Create 2 files to save the output of the script (fetch data and write to IOS.csv on successful login and write to login_issues.csv on unsuccessful login with reason)

  • In case of any exception/error, it will not stop the script, it will write the error/exceptions in login_issues.csv and continue to run the script for the remaining IP Address.

  • It will use regex to fetch all the information from router/switch like “uptime, hostname, version, memory, ios, serial, model etc“

  • All the data will be appended to devices = []

  • Finally it will write the data from devices = [] to IOS.csv file.

The Script:

from netmiko import ConnectHandler
 from netmiko.ssh_exception import NetMikoTimeoutException
 from netmiko.ssh_exception import SSHException
 from netmiko.ssh_exception import AuthenticationException
 
 import re
 
 #here is list of cisco routers ip addresses
 ip_list = ['192.168.1.1', '192.168.1.2', '192.168.1.3']
 
 #list where informations will be stored
 devices = []
 
 #clearing the old data from the CSV file and writing the headers
 f = open("IOS.csv", "w+")
 f.write("IP Address, Hostname, Uptime, Current_Version, Current_Image, Serial_Number, Device_Model, Device_Memory")
 f.write("\n")
 f.close()
 
 #clearing the old data from the CSV file and writing the headers
 f = open("login_issues.csv", "w+")
 f.write("IP Address, Status")
 f.write("\n")
 f.close()
 
 
 
 #loop all ip addresses in ip_list
 for ip in ip_list:
  cisco = {
  'device_type':'cisco_ios',
  'ip':ip,
  'username':'cisco',
  'password':'cisco',
  'ssh_strict':False,
  'fast_cli':False,
  }
 
  #handling exceptions errors
 
  try:
  net_connect = ConnectHandler(**cisco)
  except NetMikoTimeoutException:
  f = open("login_issues.csv", "a")
  f.write(ip + "," + "Device Unreachable/SSH not enabled")
  f.write("\n")
  f.close()
  continue
  except AuthenticationException:
  f = open("login_issues.csv", "a")
  f.write(ip + "," + "Authentication Failure")
  f.write("\n")
  f.close()
  continue
  except SSHException:
  f = open("login_issues.csv", "a")
  f.write(ip + "," + "SSH not enabled")
  f.write("\n")
  f.close()
  continue
 
  try:
  net_connect.enable()
 
  #handling exceptions errors
  except ValueError:
  f = open("login_issues.csv", "a")
  f.write(ip + "," + "Could be SSH Enable Password issue")
  f.write("\n")
  f.close()
  continue
 
 
  #execute show version on router and save output to output object
  sh_ver_output = net_connect.send_command('show version')
 
  #finding hostname in output using regular expressions
  regex_hostname = re.compile(r'(\S+)\suptime')
  hostname = regex_hostname.findall(sh_ver_output)
 
  #finding uptime in output using regular expressions
  regex_uptime = re.compile(r'\S+\suptime\sis\s(.+)')
  uptime = regex_uptime.findall(sh_ver_output)
  uptime = str(uptime).replace(',' ,'').replace("'" ,"")
  uptime = str(uptime)[1:-1]
 
 
  #finding version in output using regular expressions
  regex_version = re.compile(r'Cisco\sIOS\sSoftware.+Version\s([^,]+)')
  version = regex_version.findall(sh_ver_output)
 
  #finding serial in output using regular expressions
  regex_serial = re.compile(r'Processor\sboard\sID\s(\S+)')
  serial = regex_serial.findall(sh_ver_output)
 
  #finding ios image in output using regular expressions
  regex_ios = re.compile(r'System\simage\sfile\sis\s"([^ "]+)')
  ios = regex_ios.findall(sh_ver_output)
 
  #finding model in output using regular expressions
  regex_model = re.compile(r'[Cc]isco\s(\S+).*memory.')
  model = regex_model.findall(sh_ver_output)
 
 
  #finding the router's memory using regular expressions
  regex_memory = re.search(r'with (.*?) bytes of memory', sh_ver_output).group(1)
  memory = regex_memory
 
 
 
  #append results to table [hostname,uptime,version,serial,ios,model]
  devices.append([ip, hostname[0],uptime,version[0],ios[0], serial[0],model[0], memory])
 
 
 
 #print all results (for all routers) on screen
 for i in devices:
  i = ", ".join(i)
  f = open("IOS.csv", "a")
  f.write(i)
  f.write("\n")
  f.close()

IOS.csv:

This script has been tested on Cisco 2901, 7300 and 7600 and 7900 and it works perfectly fine.

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